Schedule of Investments
Principal Active High Yield ETF
March 31, 2023 (unaudited)
		Principal
BONDS — 87.01%		Amount		Value
Aerospace & Defense — 1.47%
Bombardier, Inc.
7.50%, 02/01/2029 (a)	$	465,000	$	475,025
Triumph Group, Inc.
7.75%, 08/15/2025 (b)		802,000		735,996
			$	1,211,021
Airlines — 0.08%
United Airlines 2016-1 Class B Pass Through Trust
3.65%, 07/07/2027		68,612		63,970
Auto Manufacturers — 1.82%
Ford Motor Co.
3.25%, 02/12/2032		712,000		559,601
Ford Motor Credit Co. LLC
3.38%, 11/13/2025		771,000		722,651
4.54%, 08/01/2026		221,000		209,508
			$	1,491,760
Banks — 1.46%
JPMorgan Chase & Co.
(3-month Term Secured Overnight Financing Rate + 3.13%),
4.60%, 02/01/2025 (c),(d)		1,293,000		1,202,490
Chemicals — 3.27%
Consolidated Energy Finance SA
5.63%, 10/15/2028 (a)		932,000		801,706
Kobe U.S. Midco 2, Inc.
9.25%, PIK 10.00%; 11/01/2026 (a),(e)		220,000		158,400
Olympus Water U.S. Holding Corp.
6.25%, 10/01/2029 (a)		1,574,000		1,165,085
Tronox, Inc.
4.63%, 03/15/2029 (a)		669,000		560,221
			$	2,685,412
Commercial Services — 4.02%
Albion Financing 1 SARL/Aggreko Holdings, Inc.
6.13%, 10/15/2026 (a)		801,000		712,924
Garda World Security Corp.
6.00%, 06/01/2029 (a)		146,000		116,070
9.50%, 11/01/2027 (a)		827,000		784,612
WASH Multifamily Acquisition, Inc.
5.75%, 04/15/2026 (a)		1,021,000		966,121
ZipRecruiter, Inc.
5.00%, 01/15/2030 (a)		844,000		721,620
			$	3,301,347
Computers — 1.01%
Seagate HDD Cayman
9.63%, 12/01/2032 (a)		737,310		826,279
Construction Materials — 1.48%
Smyrna Ready Mix Concrete LLC
6.00%, 11/01/2028 (a)		1,294,000		1,214,743
Diversified Financial Services — 5.62%
AerCap Holdings NV
(5-year Treasury Constant Maturity Rate + 4.54%),
5.88%, 10/10/2079 (c)		1,391,000		1,266,770

See accompanying notes.

1

Schedule of Investments
Principal Active High Yield ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Diversified Financial Services (continued)
Credit Acceptance Corp.
6.63%, 03/15/2026 (b)	$	1,210,000	$	1,128,768
Global Aircraft Leasing Co. Ltd.
6.50%, PIK 7.25%; 09/15/2024 (a),(e)		1,238,394		1,117,452
OneMain Finance Corp.
3.50%, 01/15/2027		109,000		91,479
4.00%, 09/15/2030		1,105,000		828,750
6.63%, 01/15/2028		202,000		185,196
			$	4,618,415
Electric — 4.35%
Clearway Energy Operating LLC
3.75%, 02/15/2031 (a)		1,281,000		1,104,862
GenOn Energy, Inc.
0.00%, 10/15/2020 (f),(g),(h)		3,100,000		—
NRG Energy, Inc.
3.88%, 02/15/2032 (a)		1,187,000		949,600
(5-year Treasury Constant Maturity Rate + 5.92%),
10.25%, 03/15/2028 (a),(c),(d)		185,000		176,788
Vistra Corp.
(5-year Treasury Constant Maturity Rate + 5.74%),
7.00%, 12/15/2026 (a),(c),(d)		571,000		502,480
Vistra Operations Co. LLC
4.38%, 05/01/2029 (a)		944,000		835,832
			$	3,569,562
Electronics — 1.37%
Sensata Technologies BV
4.00%, 04/15/2029 (a)		132,000		119,259
Sensata Technologies, Inc.
3.75%, 02/15/2031 (a)		1,145,000		1,001,875
			$	1,121,134
Entertainment — 7.39%
Boyne USA, Inc.
4.75%, 05/15/2029 (a)		1,475,000		1,316,842
CCM Merger, Inc.
6.38%, 05/01/2026 (a)		1,208,000		1,179,443
CDI Escrow Issuer, Inc.
5.75%, 04/01/2030 (a)		1,098,000		1,060,492
Cinemark USA, Inc.
5.25%, 07/15/2028 (a),(b)		1,118,000		967,070
International Game Technology PLC
5.25%, 01/15/2029 (a)		843,000		807,173
Lions Gate Capital Holdings LLC
5.50%, 04/15/2029 (a)		1,124,000		739,030
			$	6,070,050
Food — 3.28%
Albertsons Cos., Inc./Safeway, Inc./New Albertsons LP/Albertsons LLC
3.50%, 03/15/2029 (a)		811,000		705,646
Chobani LLC/Chobani Finance Corp., Inc.
7.50%, 04/15/2025 (a)		920,000		897,020

See accompanying notes.

2

	Schedule of Investments
	Principal Active High Yield ETF
	March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Food (continued)
Pilgrim's Pride Corp.
3.50%, 03/01/2032	$	1,196,000	$	973,305
4.25%, 04/15/2031		135,000		119,074
			$	2,695,045
Forest Products & Paper — 0.58%
Mercer International, Inc.
5.13%, 02/01/2029		557,000		476,998
Healthcare — Services — 5.22%
Acadia Healthcare Co., Inc.
5.00%, 04/15/2029 (a)		1,280,000		1,203,200
Centene Corp.
2.50%, 03/01/2031		576,000		466,445
3.38%, 02/15/2030		755,000		658,695
CHS/Community Health Systems, Inc.
6.00%, 01/15/2029 (a)		1,116,000		944,002
Tenet Healthcare Corp.
6.13%, 10/01/2028		444,000		425,538
6.13%, 06/15/2030 (a)		595,000		586,968
			$	4,284,848
Home Builders — 1.27%
Forestar Group, Inc.
3.85%, 05/15/2026 (a)		220,000		197,924
5.00%, 03/01/2028 (a)		945,000		845,775
			$	1,043,699
Insurance — 1.73%
Acrisure LLC/Acrisure Finance, Inc.
4.25%, 02/15/2029 (a)		139,000		118,497
7.00%, 11/15/2025 (a)		549,000		514,534
Voya Financial, Inc.
(3-month USD LIBOR + 3.58%),
5.65%, 05/15/2053 (c)		820,000		791,300
			$	1,424,331
Investment Companies — 0.88%
Compass Group Diversified Holdings LLC
5.25%, 04/15/2029 (a)		821,000		722,821
Iron & Steel — 0.59%
TMS International Corp.
6.25%, 04/15/2029 (a)		628,000		484,123
Leisure Time — 1.42%
Life Time, Inc.
5.75%, 01/15/2026 (a)		1,200,000		1,165,710
Lodging — 0.80%
Wynn Las Vegas LLC/Wynn Las Vegas Capital Corp.
5.25%, 05/15/2027 (a)		271,000		256,095
Wynn Macau Ltd.
5.63%, 08/26/2028 (a)		470,000		399,744
			$	655,839

See accompanying notes.

3

Schedule of Investments
Principal Active High Yield ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Media — 6.87%
CCO Holdings LLC/CCO Holdings Capital Corp.
4.25%, 02/01/2031 (a)	$	1,302,000	$	1,064,593
4.75%, 02/01/2032 (a)		411,000		345,179
Directv Financing LLC/Directv Financing Co.-Obligor, Inc.
5.88%, 08/15/2027 (a)		1,282,000		1,161,107
DISH DBS Corp.
5.13%, 06/01/2029		136,000		72,420
5.25%, 12/01/2026 (a)		13,284		10,599
5.88%, 11/15/2024		397,000		353,989
7.38%, 07/01/2028		669,000		381,772
DISH Network Corp.
11.75%, 11/15/2027 (a)		546,000		529,620
Scripps Escrow II, Inc.
5.38%, 01/15/2031 (a)		407,000		279,813
Sirius XM Radio, Inc.
3.13%, 09/01/2026 (a)		1,110,000		1,001,220
UPC Holding BV
5.50%, 01/15/2028 (a)		494,000		442,422
			$	5,642,734
Mining — 3.27%
Copper Mountain Mining Corp.
8.00%, 04/09/2026 (a)		1,164,060		1,105,857
First Quantum Minerals Ltd.
6.88%, 10/15/2027 (a)		315,000		303,670
Novelis Corp.
3.88%, 08/15/2031 (a)		754,000		635,049
Taseko Mines Ltd.
7.00%, 02/15/2026 (a)		707,000		641,425
			$	2,686,001
Oil & Gas — 5.97%
Aethon United BR LP/Aethon United Finance Corp.
8.25%, 02/15/2026 (a)		1,098,000		1,077,380
Antero Resources Corp.
7.63%, 02/01/2029 (a),(b)		850,000		869,125
Apache Corp.
4.75%, 04/15/2043		59,000		44,289
5.10%, 09/01/2040		753,000		638,167
5.25%, 02/01/2042		42,000		35,268
Ascent Resources Utica Holdings LLC/ARU Finance Corp.
7.00%, 11/01/2026 (a)		402,000		388,573
Comstock Resources, Inc.
5.88%, 01/15/2030 (a)		494,000		424,419
MEG Energy Corp.
7.13%, 02/01/2027 (a)		767,000		782,412
Occidental Petroleum Corp.
6.13%, 01/01/2031		138,000		143,175
6.63%, 09/01/2030		478,000		503,415
			$	4,906,223
Oil & Gas Services — 0.98%
Archrock Partners LP/Archrock Partners Finance Corp.
6.25%, 04/01/2028 (a)		834,000		800,640

See accompanying notes.

4

Schedule of Investments
Principal Active High Yield ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Packaging & Containers — 1.56%
Clydesdale Acquisition Holdings, Inc.
6.63%, 04/15/2029 (a)	$	132,000	$	127,050
8.75%, 04/15/2030 (a)		473,000		429,834
LABL, Inc.
5.88%, 11/01/2028 (a)		100,000		88,856
8.25%, 11/01/2029 (a)		389,000		331,710
9.50%, 11/01/2028		305,000		307,669
			$	1,285,119
Pharmaceuticals — 2.35%
BellRing Brands, Inc.
7.00%, 03/15/2030 (a)		724,000		733,390
Jazz Securities DAC
4.38%, 01/15/2029 (a)		1,305,000		1,200,600
			$	1,933,990
Pipelines — 7.91%
Antero Midstream Partners LP/Antero Midstream Finance Corp.
5.38%, 06/15/2029 (a)		748,000		703,973
5.75%, 03/01/2027 (a)		491,000		479,717
CNX Midstream Partners LP
4.75%, 04/15/2030 (a)		1,102,000		947,720
Crestwood Midstream Partners LP/Crestwood Midstream Finance Corp.
5.63%, 05/01/2027 (a)		1,198,000		1,154,165
EnLink Midstream LLC
6.50%, 09/01/2030 (a)		771,000		779,643
Hess Midstream Operations LP
4.25%, 02/15/2030 (a)		907,000		810,042
Kinetik Holdings LP
5.88%, 06/15/2030 (a)		1,215,000		1,169,438
Targa Resources Partners LP/Targa Resources Partners Finance Corp.
4.88%, 02/01/2031		487,000		455,678
			$	6,500,376
REITs — 2.19%
CBL & Associates LP
0.00%, 12/15/2026 (f),(g),(h)		6,000,000		—
HAT Holdings I LLC/HAT Holdings II LLC
3.38%, 06/15/2026 (a)		851,000		738,243
Ladder Capital Finance Holdings LLLP/Ladder Capital Finance Corp.
4.75%, 06/15/2029 (a)		1,462,000		1,056,777
			$	1,795,020
Retail — 4.55%
Bath & Body Works, Inc.
5.25%, 02/01/2028		248,000		236,840
6.63%, 10/01/2030 (a)		415,000		404,575
9.38%, 07/01/2025 (a),(b)		143,000		152,776
Dave & Buster's, Inc.
7.63%, 11/01/2025 (a)		764,000		778,573
Fertitta Entertainment LLC/Fertitta Entertainment Finance Co., Inc.
4.63%, 01/15/2029 (a)		569,000		499,411
6.75%, 01/15/2030 (a)		392,000		322,510
LSF9 Atlantis Holdings LLC/Victra Finance Corp.
7.75%, 02/15/2026 (a)		824,000		748,465

See accompanying notes.

5

	Schedule of Investments
	Principal Active High Yield ETF
	March 31, 2023 (unaudited)
			Principal
BONDS (continued)			Amount		Value
Retail (continued)
Park River Holdings, Inc.
	5.63%, 02/01/2029 (a)	$	485,000	$	330,554
Patrick Industries, Inc.
	4.75%, 05/01/2029 (a)		302,000		262,036
				$	3,735,740
Telecommunications — 1.15%
Maxar Technologies, Inc.
	7.75%, 06/15/2027 (a)		903,000		943,579
Transportation — 1.10%
Watco Cos. LLC/Watco Finance Corp.
	6.50%, 06/15/2027 (a)		963,000		902,641
TOTAL BONDS				$	71,461,660
			Principal
SENIOR FLOATING RATE INTERESTS — 7.39%			Amount		Value
Airlines — 5.79%
AAdvantage Loyalty IP Ltd., 2021 Term Loan B
	(3-month USD LIBOR + 4.75%),
	9.56%, 04/20/2028	$	1,355,000	$	1,374,011
Mileage Plus Holdings LLC, 2020 Term Loan B
	(3-month USD LIBOR + 5.25%),
	10.21%, 06/21/2027		1,109,474		1,149,836
United Airlines, Inc., 2021 Term Loan B
	(3-month USD LIBOR + 3.75%),
	8.57%, 04/21/2028		2,249,825		2,230,139
				$	4,753,986
Forest Products & Paper — 1.60%
Spectrum Group Buyer, Inc., 2022 Term Loan B
	(3-month Term Secured Overnight Financing Rate + 6.50%),
	11.32%, 05/19/2028		1,394,766		1,318,054
TOTAL SENIOR FLOATING RATE INTERESTS				$	6,072,040
INVESTMENT COMPANIES — 5.75%			Shares Held		Value
Money Market Funds — 5.75%
Principal Government Money Market Fund — Class R-6 4.72% (i),(j),(k)			1,870,490	$	1,870,490
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (k)			2,855,842		2,855,842
TOTAL INVESTMENT COMPANIES				$	4,726,332
Total Investments				$	82,260,032
Other Assets and Liabilities — (0.15)%					(127,177	)
Total Net Assets — 100.00%				$	82,132,855
(a)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $57,382,444 or 69.87% of net assets.
(b)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $1,843,348 or
	2.24% of net assets.
(c)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or
	floating rate in the future.
(d)	Perpetual security. Perpetual securities pay an indefinite stream of interest, but they may be called by the issuer at an earlier
	date. Date shown, if any, reflects the next call date or final legal maturity date. Rate shown is as of period end.
(e)	Payment in kind; the issuer has the option of paying additional securities in lieu of cash.
See accompanying notes.		6

Schedule of Investments
Principal Active High Yield ETF
March 31, 2023 (unaudited)

^(f) Non-income producing security.

^(g) The value of these investments was determined using significant unobservable inputs, in good faith by the Advisor, under procedures established and periodically reviewed by the Board of Trustees.

^(h) Security is defaulted.

⁽ⁱ⁾ Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).

Please see Affiliated Securities sub-schedule for transactional information.

^(j) Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of these securities totaled $1,870,490 or 2.28% of net assets.

^(k) Current yield shown is as of period end.

Portfolio Summary
Sector					Percent
Consumer, Cyclical					23.11	%
Consumer, Non-cyclical					14.87	%
Energy					14.86	%
Financial					11.89	%
Basic Materials					9.31	%
Communications					8.02	%
Industrial					6.98	%
Money Market Funds					5.75	%
Utilities					4.35	%
Technology					1.01	%
Other Assets and Liabilities					(0.15	)%
TOTAL NET ASSETS					100.00	%
			June 30, 2022		Purchases			Sales		March 31, 2023
Affiliated Securities			Value		Cost			Proceeds		Value
Principal Government Money
Market Fund — Class R-6 4.72%		$	—	$	13,766,637		$	11,896,147	$	1,870,490
Principal Government Money
Market Fund — Institutional Class
4.67	%		5,781,485		33,322,007			39,103,492		—
		$	5,781,485	$	47,088,644		$	50,999,639	$	1,870,490
								Realized Gain
					Realized			from		Change in
					Gain/(Loss) on			Capital Gain		Unrealized
			Income (a)		Investments			Distributions		Gain/(Loss)
Principal Government Money
Market Fund — Class R-6 4.72%		$	—	$	—		$	—	$	—
Principal Government Money
Market Fund — Institutional Class
4.67	%		—		—			—		—
		$	—	$	—		$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

7

	Schedule of Investments
	Principal Healthcare Innovators ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 99.86%		Shares Held		Value
Biotechnology — 62.97%
2seventy bio, Inc. (a)		5,988	$	61,078
4D Molecular Therapeutics, Inc. (a)		6,533		112,302
Aadi Bioscience, Inc. (a)		3,869		28,012
Absci Corp. (a)		17,523		30,665
ACADIA Pharmaceuticals, Inc. (a)		22,943		431,787
Adicet Bio, Inc. (a)		6,149		35,418
ADMA Biologics, Inc. (a)		31,369		103,831
Affimed NV (a)		27,677		20,636
Agenus, Inc. (a)		43,100		65,512
Akero Therapeutics, Inc. (a)		6,690		255,959
Allogene Therapeutics, Inc. (a)		20,640		101,962
Allovir, Inc. (a)		14,188		55,901
Alnylam Pharmaceuticals, Inc. (a)		7,878		1,578,121
ALX Oncology Holdings, Inc. (a)		6,617		29,909
Amicus Therapeutics, Inc. (a)		39,458		437,589
AnaptysBio, Inc. (a)		4,277		93,068
Anavex Life Sciences Corp. (a),(b)		11,586		99,292
ANI Pharmaceuticals, Inc. (a)		2,712		107,721
Apellis Pharmaceuticals, Inc. (a)		15,203		1,002,790
Arbutus Biopharma Corp. (a)		26,491		80,268
Arcellx, Inc. (a)		6,557		202,021
Arcturus Therapeutics Holdings, Inc. (a)		4,480		107,386
Arcus Biosciences, Inc. (a)		10,156		185,245
Arcutis Biotherapeutics, Inc. (a)		8,848		97,328
Arrowhead Pharmaceuticals, Inc. (a)		14,831		376,707
Atara Biotherapeutics, Inc. (a)		15,841		45,939
Atea Pharmaceuticals, Inc. (a)		13,700		45,895
Aurinia Pharmaceuticals, Inc. (a)		23,731		260,092
Avidity Biosciences, Inc. (a)		8,048		123,537
Axsome Therapeutics, Inc. (a)		6,192		381,923
Beam Therapeutics, Inc. (a),(b)		9,902		303,199
Bio-Rad Laboratories, Inc., Class A (a)		4,074		1,951,527
BioCryst Pharmaceuticals, Inc. (a)		26,615		221,969
Biohaven Ltd. (a)		6,240		85,238
Bluebird Bio, Inc. (a)		12,598		40,062
Blueprint Medicines Corp. (a)		8,424		378,996
Bridgebio Pharma, Inc. (a)		21,678		359,421
C4 Therapeutics, Inc. (a)		8,107		25,456
Cara Therapeutics, Inc. (a)		8,595		42,201
Caribou Biosciences, Inc. (a)		9,560		50,764
Cassava Sciences, Inc. (a),(b)		5,766		139,076
Celldex Therapeutics, Inc. (a)		6,849		246,427
Celularity, Inc. (a)		25,241		15,642
Cerevel Therapeutics Holdings, Inc. (a)		21,870		533,409
Chinook Therapeutics, Inc. (a)		9,098		210,619
Cogent Biosciences, Inc. (a)		9,785		105,580
Crinetics Pharmaceuticals, Inc. (a)		7,989		128,303
CTI BioPharma Corp. (a)		19,062		80,060
Cullinan Oncology, Inc. (a)		7,216		73,820
Cytek Biosciences, Inc. (a)		19,515		179,343
Cytokinetics, Inc. (a)		13,456		473,517
Day One Biopharmaceuticals, Inc. (a)		10,550		141,053
Deciphera Pharmaceuticals, Inc. (a)		9,766		150,885
Denali Therapeutics, Inc. (a)		18,671		430,180
Design Therapeutics, Inc. (a)		8,351		48,185
DICE Therapeutics, Inc. (a)		6,608		189,319
Dyne Therapeutics, Inc. (a)		8,089		93,185
Edgewise Therapeutics, Inc. (a)		7,984		53,253

See accompanying notes.

8

	Schedule of Investments
	Principal Healthcare Innovators ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Biotechnology (continued)
Editas Medicine, Inc. (a)		10,370	$	75,182
Eiger BioPharmaceuticals, Inc. (a)		8,579		7,695
Emergent BioSolutions, Inc. (a)		7,424		76,913
EQRx, Inc. (a)		62,956		122,135
Erasca, Inc. (a)		18,190		54,752
Esperion Therapeutics, Inc. (a)		11,181		17,778
Evolus, Inc. (a)		9,090		76,901
Fate Therapeutics, Inc. (a)		13,718		78,193
FibroGen, Inc. (a)		13,687		255,399
Geron Corp. (a)		56,509		122,625
Gossamer Bio, Inc. (a)		13,994		17,632
Ideaya Biosciences, Inc. (a)		7,115		97,689
IGM Biosciences, Inc. (a),(b)		4,580		62,929
ImmunityBio, Inc. (a)		56,271		102,413
ImmunoGen, Inc. (a)		31,819		122,185
Immunovant, Inc. (a)		18,981		294,395
Inhibrx, Inc. (a)		5,676		107,106
Inovio Pharmaceuticals, Inc. (a)		41,065		33,673
Insmed, Inc. (a)		19,378		330,395
Instil Bio, Inc. (a)		20,401		13,481
Intellia Therapeutics, Inc. (a)		10,580		394,317
Intercept Pharmaceuticals, Inc. (a)		6,512		87,456
Intra-Cellular Therapies, Inc. (a)		13,226		716,188
Invivyd, Inc. (a)		18,404		22,085
Ionis Pharmaceuticals, Inc. (a)		19,665		702,827
Iovance Biotherapeutics, Inc. (a)		22,639		138,324
IVERIC bio, Inc. (a)		16,822		409,279
Karuna Therapeutics, Inc. (a)		4,625		840,085
Karyopharm Therapeutics, Inc. (a)		13,663		53,149
Keros Therapeutics, Inc. (a)		3,757		160,424
Kezar Life Sciences, Inc. (a)		11,020		34,493
Kiniksa Pharmaceuticals Ltd., Class A (a)		5,699		61,321
Kinnate Biopharma, Inc. (a)		7,715		48,219
Kodiak Sciences, Inc. (a)		8,934		55,391
Krystal Biotech, Inc. (a)		3,718		297,663
Kymera Therapeutics, Inc. (a)		8,064		238,936
Lexicon Pharmaceuticals, Inc. (a)		31,571		76,718
Ligand Pharmaceuticals, Inc. (a)		2,421		178,089
Liquidia Corp. (a),(b)		11,713		80,937
MacroGenics, Inc. (a)		11,047		79,207
Mersana Therapeutics, Inc. (a)		14,911		61,284
Mirati Therapeutics, Inc. (a)		7,752		288,219
Monte Rosa Therapeutics, Inc. (a)		7,996		62,289
Myriad Genetics, Inc. (a)		11,846		275,183
Nektar Therapeutics (a)		29,005		20,388
NeoGenomics, Inc. (a)		19,545		340,278
NGM Biopharmaceuticals, Inc. (a)		13,718		55,969
Nkarta, Inc. (a)		7,582		26,916
Novavax, Inc. (a),(b)		11,195		77,581
Nurix Therapeutics, Inc. (a)		7,510		66,689
Nuvalent, Inc., Class A (a)		6,633		173,055
Nuvation Bio, Inc. (a)		35,408		58,777
Phathom Pharmaceuticals, Inc. (a),(b)		6,603		47,145
PhenomeX, Inc. (a)		16,211		18,805
Point Biopharma Global, Inc. (a)		15,649		113,768
Praxis Precision Medicines, Inc. (a),(b)		14,772		11,951
Precigen, Inc. (a),(b)		35,748		37,893
Prothena Corp. PLC (a)		6,642		321,938

See accompanying notes.

9

	Schedule of Investments
	Principal Healthcare Innovators ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Biotechnology (continued)
Provention Bio, Inc. (a)		13,173	$	317,469
PTC Therapeutics, Inc. (a)		10,046		486,628
RAPT Therapeutics, Inc. (a)		4,610		84,593
Recursion Pharmaceuticals, Inc., Class A (a)		23,378		155,931
REGENXBIO, Inc. (a)		6,380		120,646
Relay Therapeutics, Inc. (a)		17,091		281,489
Replimune Group, Inc. (a)		7,320		129,271
REVOLUTION Medicines, Inc. (a)		12,709		275,277
Rigel Pharmaceuticals, Inc. (a)		39,926		52,702
Rocket Pharmaceuticals, Inc. (a)		9,630		164,962
Sage Therapeutics, Inc. (a)		8,490		356,240
Sana Biotechnology, Inc. (a),(b)		27,948		91,390
Sangamo Therapeutics, Inc. (a)		24,125		42,460
Sarepta Therapeutics, Inc. (a)		12,087		1,665,951
Scilex Holding Co. (a),(b)		10,078		82,640
Seagen, Inc. (a)		12,157		2,461,428
Seer, Inc. (a)		9,872		38,106
SpringWorks Therapeutics, Inc. (a)		9,131		235,032
Stoke Therapeutics, Inc. (a)		6,276		52,279
Sutro Biopharma, Inc. (a)		9,381		43,340
Syndax Pharmaceuticals, Inc. (a)		8,402		177,450
Tarsus Pharmaceuticals, Inc. (a)		4,417		55,522
TG Therapeutics, Inc. (a)		22,515		338,626
Theravance Biopharma, Inc. (a)		10,406		112,905
TransMedics Group, Inc. (a)		4,594		347,904
Travere Therapeutics, Inc. (a)		9,183		206,526
Twist Bioscience Corp. (a)		8,023		120,987
Ultragenyx Pharmaceutical, Inc. (a)		9,910		397,391
Vaxart, Inc. (a)		25,020		18,933
Ventyx Biosciences, Inc. (a)		8,236		275,906
Vera Therapeutics, Inc. (a)		4,568		35,448
Veracyte, Inc. (a)		10,742		239,547
Vericel Corp. (a)		7,073		207,380
Verve Therapeutics, Inc. (a)		8,466		122,080
Viridian Therapeutics, Inc. (a)		5,794		147,399
VistaGen Therapeutics, Inc. (a)		155,904		19,441
Xencor, Inc. (a)		8,677		242,002
Zentalis Pharmaceuticals, Inc. (a)		8,250		141,900
			$	32,456,471
Chemicals — 0.09%
Codexis, Inc. (a)		11,414		47,254
Electronics — 0.28%
Mesa Laboratories, Inc.		833		145,550
Healthcare — Products — 21.38%
10X Genomics, Inc., Class A (a)		13,582		757,740
Adaptive Biotechnologies Corp. (a)		21,254		187,673
Akoya Biosciences, Inc. (a)		6,122		50,078
Alphatec Holdings, Inc. (a)		15,802		246,511
AngioDynamics, Inc. (a)		6,361		65,773
Artivion, Inc. (a)		6,909		90,508
AtriCure, Inc. (a)		6,749		279,746
Axogen, Inc. (a)		6,843		64,666
Axonics, Inc. (a)		6,860		374,282
BioLife Solutions, Inc. (a)		6,428		139,809
Bionano Genomics, Inc. (a),(b)		45,224		50,199
Butterfly Network, Inc. (a),(b)		26,272		49,391

See accompanying notes.

10

	Schedule of Investments
	Principal Healthcare Innovators ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Healthcare — Products (continued)
Cardiovascular Systems, Inc. (a)		6,463	$	128,355
CareDx, Inc. (a)		7,970		72,846
Cerus Corp. (a)		27,576		81,901
Cutera, Inc. (a)		2,933		69,277
Exact Sciences Corp. (a)		24,596		1,667,855
Glaukos Corp. (a)		6,771		339,227
Inari Medical, Inc. (a)		7,424		458,358
Inogen, Inc. (a)		3,738		46,650
Inspire Medical Systems, Inc. (a)		3,980		931,599
iRhythm Technologies, Inc. (a)		4,216		522,910
MaxCyte, Inc. (a)		15,897		78,690
MiMedx Group, Inc. (a)		20,029		68,299
NanoString Technologies, Inc. (a)		7,684		76,072
Natera, Inc. (a)		13,596		754,850
Nevro Corp. (a)		5,084		183,787
Novocure Ltd. (a)		14,456		869,384
NuVasive, Inc. (a)		7,465		308,379
OmniAb, Inc., Earnout Shares (a)		977		—
OmniAb, Inc., Earnout Shares (a)		977		—
OraSure Technologies, Inc. (a)		13,207		79,902
Orthofix Medical, Inc. (a)		3,614		60,534
OrthoPediatrics Corp. (a)		3,023		133,889
Pacific Biosciences of California, Inc. (a)		32,476		376,072
Paragon 28, Inc. (a)		11,036		188,385
PROCEPT BioRobotics Corp. (a)		6,478		183,975
Pulmonx Corp. (a)		5,929		66,286
Quanterix Corp. (a)		6,421		72,365
Quantum-Si, Inc. (a)		21,097		37,131
SI-BONE, Inc. (a)		5,363		105,490
Silk Road Medical, Inc. (a)		5,477		214,315
SomaLogic, Inc. (a)		29,388		74,939
Tactile Systems Technology, Inc. (a)		4,578		75,171
Treace Medical Concepts, Inc. (a)		8,008		201,721
ViewRay, Inc. (a)		27,716		95,897
Zimvie, Inc. (a)		5,399		39,035
			$	11,019,922
Healthcare — Services — 0.13%
Inotiv, Inc. (a),(b)		4,131		17,887
Nano-X Imaging Ltd. (a),(b)		8,149		47,020
			$	64,907
Miscellaneous Manufacturers — 0.14%
Sight Sciences, Inc. (a)		8,241		72,026
Pharmaceuticals — 14.28%
Aclaris Therapeutics, Inc. (a)		9,759		78,950
Agios Pharmaceuticals, Inc. (a)		8,088		185,781
Alector, Inc. (a)		12,596		77,969
Alkermes PLC (a)		23,115		651,612
Amneal Pharmaceuticals, Inc. (a)		27,041		37,587
Amylyx Pharmaceuticals, Inc. (a)		9,290		272,569
Anika Therapeutics, Inc. (a)		2,477		71,139
Arvinas, Inc. (a)		7,621		208,206
Bioxcel Therapeutics, Inc. (a)		5,034		93,935
Chimerix, Inc. (a)		19,566		24,653
Coherus Biosciences, Inc. (a)		12,019		82,210
Collegium Pharmaceutical, Inc. (a)		5,348		128,299

See accompanying notes.

11

		Schedule of Investments
		Principal Healthcare Innovators ETF
		March 31, 2023 (unaudited)
COMMON STOCKS (continued)			Shares Held		Value
Pharmaceuticals (continued)
Eagle Pharmaceuticals, Inc. (a)			2,221	$	63,010
Elanco Animal Health, Inc. (a)			66,017		620,560
Enanta Pharmaceuticals, Inc. (a)			3,071		124,191
Fulcrum Therapeutics, Inc. (a)			9,402		26,796
Heron Therapeutics, Inc. (a)			19,387		29,274
Heska Corp. (a)			1,641		160,194
KalVista Pharmaceuticals, Inc. (a)			6,367		50,045
Kura Oncology, Inc. (a)			9,775		119,548
Lyell Immunopharma, Inc. (a),(b)			35,322		83,360
Madrigal Pharmaceuticals, Inc. (a)			2,528		612,433
MannKind Corp. (a)			38,580		158,178
Mirum Pharmaceuticals, Inc. (a)			5,632		135,281
Morphic Holding, Inc. (a)			5,861		220,608
Ocugen, Inc. (a)			36,876		31,459
Ocular Therapeutix, Inc. (a)			14,316		75,445
Perrigo Co. PLC			18,774		673,423
PMV Pharmaceuticals, Inc. (a)			7,214		34,411
Prometheus Biosciences, Inc. (a)			5,842		626,964
Protagonist Therapeutics, Inc. (a)			8,216		188,968
Reata Pharmaceuticals, Inc., Class A (a)			4,937		448,872
Relmada Therapeutics, Inc. (a)			6,336		14,319
Revance Therapeutics, Inc. (a)			10,663		343,455
Senseonics Holdings, Inc. (a),(b)			73,765		52,373
Seres Therapeutics, Inc. (a)			18,712		106,097
SIGA Technologies, Inc.			11,303		64,992
Vaxcyte, Inc. (a)			9,406		352,537
Y-mAbs Therapeutics, Inc. (a)			6,781		33,973
				$	7,363,676
Software — 0.26%
Outset Medical, Inc. (a)			7,363		135,479
Transportation — 0.33%
CryoPort, Inc. (a)			7,057		169,368
TOTAL COMMON STOCKS				$	51,474,653
INVESTMENT COMPANIES — 1.47%			Shares Held		Value
Money Market Funds — 1.47%
Principal Government Money Market Fund — Class R-6 4.72% (c),(d),(e)			667,298	$	667,298
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (e)			88,040		88,040
TOTAL INVESTMENT COMPANIES				$	755,338
Total Investments				$	52,229,991
Other Assets and Liabilities — (1.33)%					(684,579	)
Total Net Assets — 100.00%				$	51,545,412
(a)	Non-income producing security.
(b)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $628,444 or
	1.22% of net assets.
(c)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(d)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $667,298 or 1.29% of net assets.
(e)	Current yield shown is as of period end.
See accompanying notes.		12

			Schedule of Investments
			Principal Healthcare Innovators ETF
			March 31, 2023 (unaudited)
Portfolio Summary
Sector					Percent
Consumer, Non-cyclical						98.76	%
Money Market Funds						1.47	%
Industrial						0.75	%
Technology						0.26	%
Basic Materials						0.09	%
Other Assets and Liabilities						(1.33	)%
TOTAL NET ASSETS						100.00	%
			June 30, 2022		Purchases					Sales		March 31, 2023
Affiliated Securities			Value			Cost				Proceeds		Value
Principal Government Money
Market Fund — Class R-6 4.72%		$	—		$	5,482,808			$	4,815,510	$	667,298
Principal Government Money
Market Fund — Institutional Class
4.67	%		1,097,187			11,867,549				12,964,736		—
		$	1,097,187	$	17,350,357			$	17,780,246		$	667,298
									Realized Gain
						Realized				from		Change in
					Gain/(Loss) on				Capital Gain			Unrealized
			Income (a)		Investments				Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Class R-6 4.72%		$	—		$	—			$	—	$	—
Principal Government Money
Market Fund — Institutional Class
4.67	%		—			—				—		—
		$	—		$	—			$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

13

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 97.77%	Shares Held		Value
Advertising — 0.55%
Dentsu Group, Inc.	500	$	17,511
Hakuhodo DY Holdings, Inc.	1,000		11,260
Publicis Groupe SA (a)	383		29,815
WPP PLC	2,183		25,814
		$	84,400
Aerospace & Defense — 1.26%
Airbus SE	195		26,071
BAE Systems PLC	4,150		50,304
Dassault Aviation SA	99		19,605
Elbit Systems Ltd.	30		5,081
MTU Aero Engines AG	34		8,503
Rheinmetall AG	59		17,506
Rolls-Royce Holdings PLC (a)	9,577		17,605
Safran SA	163		24,137
Singapore Technologies Engineering Ltd.	800		2,200
Thales SA	146		21,589
		$	192,601
Agriculture — 0.92%
British American Tobacco PLC	1,661		58,202
Imperial Brands PLC	1,525		35,066
Japan Tobacco, Inc.	1,500		31,610
Wilmar International Ltd.	5,100		16,134
		$	141,012
Airlines — 0.28%
Air Canada (a)	517		7,326
Deutsche Lufthansa AG (a)	1,309		14,565
Qantas Airways Ltd. (a)	2,831		12,528
Singapore Airlines Ltd.	2,000		8,611
		$	43,030
Apparel — 2.18%
Burberry Group PLC	269		8,581
Gildan Activewear, Inc.	475		15,781
Hermes International	21		42,452
Kering SA	54		35,138
LVMH Moet Hennessy Louis Vuitton SE	245		224,359
Puma SE	121		7,461
		$	333,772
Auto Manufacturers — 3.09%
Bayerische Motoren Werke AG	444		48,604
Daimler Truck Holding AG	540		18,219
Ferrari NV	119		32,173
Honda Motor Co. Ltd.	1,500		39,654
Isuzu Motors Ltd.	1,200		14,271
Mazda Motor Corp.	1,300		11,994
Mercedes-Benz Group AG	544		41,758
Renault SA	365		14,884
Stellantis NV	2,640		47,916
Subaru Corp.	1,100		17,518
Toyota Motor Corp.	9,400		133,097
Volkswagen AG	39		6,683
Volvo AB, Class B	1,296		26,703
Volvo AB, Class A	614		13,192

See accompanying notes.

14

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Auto Manufacturers (continued)
Volvo Car AB, Class B (a)	1,444	$	6,288
		$	472,954
Auto Parts & Equipment — 0.28%
Cie Generale des Etablissements Michelin SCA	361		11,019
Continental AG	92		6,876
NGK Insulators Ltd.	900		11,876
Valeo SA	634		13,002
		$	42,773
Banks — 9.78%
ABN AMRO Bank NV, GDR (b)	862		13,667
AIB Group PLC	2,982		12,102
ANZ Group Holdings Ltd.	1,511		23,160
Banco Bilbao Vizcaya Argentaria SA	6,881		49,036
Banco Santander SA	11,499		42,725
Bank Hapoalim BM	2,416		19,987
Bank Leumi Le-Israel BM	2,822		21,188
Bank of Ireland Group PLC	2,303		23,288
Bank of Montreal	551		49,078
Bank of Nova Scotia	537		27,047
Banque Cantonale Vaudoise	135		12,733
Barclays PLC	7,376		13,266
BNP Paribas SA	752		45,026
BOC Hong Kong Holdings Ltd.	3,500		10,901
CaixaBank SA	4,936		19,186
Canadian Imperial Bank of Commerce	448		18,997
Chiba Bank Ltd.	2,100		13,523
Commerzbank AG	1,612		16,961
Commonwealth Bank of Australia	759		49,883
Concordia Financial Group Ltd.	3,700		13,599
Credit Agricole SA	1,776		20,027
Danske Bank A/S (a)	426		8,558
DBS Group Holdings Ltd.	1,600		39,675
Deutsche Bank AG	1,094		11,100
DNB Bank ASA	720		12,884
Erste Group Bank AG	498		16,472
FinecoBank Banca Fineco SpA	983		15,074
Hang Seng Bank Ltd.	695		9,890
HSBC Holdings PLC	17,656		119,727
ING Groep NV (a)	2,714		32,171
Intesa Sanpaolo SpA	5,897		15,141
Israel Discount Bank Ltd., Class A	3,883		18,950
KBC Group NV	280		19,222
Lloyds Banking Group PLC	53,580		31,511
Macquarie Group Ltd.	191		22,427
Mediobanca Banca di Credito Finanziario SpA	1,487		14,946
Mitsubishi UFJ Financial Group, Inc.	10,600		67,692
Mizrahi Tefahot Bank Ltd.	509		15,881
Mizuho Financial Group, Inc.	3,000		42,433
National Australia Bank Ltd.	1,487		27,553
National Bank of Canada	373		26,680
NatWest Group PLC	2,880		9,365
Nordea Bank Abp	1,352		14,412
Oversea-Chinese Banking Corp. Ltd.	3,300		30,674
Royal Bank of Canada	733		70,100
Skandinaviska Enskilda Banken AB, Class A	1,766		19,457
Societe Generale SA	889		20,039

See accompanying notes.

15

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Banks (continued)
Standard Chartered PLC	2,641	$	20,010
Sumitomo Mitsui Financial Group, Inc.	1,200		47,883
Svenska Handelsbanken AB, Class A	972		8,414
Swedbank AB, Class A	1,063		17,427
Toronto-Dominion Bank	838		50,193
UBS Group AG (a)	2,250		47,437
UniCredit SpA	783		14,784
United Overseas Bank Ltd.	800		17,890
Westpac Banking Corp.	1,720		24,903
		$	1,496,355
Beverages — 2.27%
Anheuser-Busch InBev SA	410		27,270
Asahi Group Holdings Ltd.	600		22,251
Budweiser Brewing Co. APAC Ltd. (a),(b)	1,900		5,797
Carlsberg AS, Class B	73		11,297
Coca-Cola Europacific Partners PLC	479		28,352
Coca-Cola HBC AG (a)	558		15,233
Davide Campari-Milano NV	1,258		15,348
Diageo PLC	974		43,423
Endeavour Group Ltd.	2,007		9,083
Heineken Holding NV	202		18,522
Heineken NV	390		41,898
JDE Peet's NV	647		18,819
Kirin Holdings Co. Ltd.	1,300		20,522
Pernod Ricard SA	175		39,609
Remy Cointreau SA	36		6,559
Suntory Beverage & Food Ltd.	400		14,867
Treasury Wine Estates Ltd.	946		8,265
		$	347,115
Biotechnology — 0.61%
Argenx SE (a)	12		4,435
Argenx SE (a)	24		8,868
Bachem Holding AG, Class B (a)	66		6,593
CSL Ltd.	204		39,314
Genmab A/S (a)	69		26,005
Swedish Orphan Biovitrum AB (a)	316		7,353
		$	92,568
Chemicals — 2.67%
Air Liquide SA	215		35,954
Arkema SA	145		14,278
BASF SE	690		36,188
Brenntag SE	226		16,961
Chr Hansen Holding A/S	90		6,826
Clariant AG (a)	497		8,208
Croda International PLC	104		8,337
EMS-Chemie Holding AG (a)	3		2,472
Evonik Industries AG	311		6,530
Givaudan SA	5		16,247
ICL Group Ltd.	2,107		14,138
Johnson Matthey PLC	505		12,357
Nippon Sanso Holdings Corp.	700		12,558
Nissan Chemical Corp.	400		18,046
Nitto Denko Corp.	300		19,318
Novozymes A/S, Class B	150		7,662
Nutrien Ltd.	401		29,614

See accompanying notes.

16

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Chemicals (continued)
OCI NV (a)	432	$	14,645
Shin-Etsu Chemical Co. Ltd.	1,500		48,296
Solvay SA (a)	199		22,736
Sumitomo Chemical Co. Ltd.	3,800		12,736
Symrise AG	27		2,934
Tosoh Corp.	900		12,181
Umicore SA	441		14,927
Yara International ASA	341		14,783
		$	408,932
Commercial Services — 2.44%
Adecco Group AG (a)	191		6,920
Adyen NV (a),(b)	9		14,243
Amadeus IT Group SA (a)	394		26,347
Ashtead Group PLC	396		24,220
Brambles Ltd.	2,124		19,068
Bureau Veritas SA	82		2,354
Edenred	357		21,116
Element Fleet Management Corp.	1,000		13,134
Experian PLC	412		13,519
IDP Education Ltd.	353		6,444
Intertek Group PLC	351		17,549
Persol Holdings Co. Ltd.	600		11,993
Randstad NV	222		13,145
Recruit Holdings Co. Ltd.	1,300		35,737
RELX PLC	1,555		50,220
Rentokil Initial PLC	1,437		10,487
Ritchie Bros Auctioneers, Inc.	203		11,422
Secom Co. Ltd.	400		24,595
Securitas AB, Class B	778		6,917
SGS SA	2		4,396
TOPPAN, Inc.	700		14,050
Transurban Group	1,811		17,202
Worldline SA (a),(b)	192		8,144
		$	373,222
Computers — 1.45%
Bechtle AG	139		6,631
Capgemini SE	145		26,851
CGI, Inc. (a)	393		37,875
Check Point Software Technologies Ltd. (a)	90		11,700
Computershare Ltd.	544		7,851
Itochu Techno-Solutions Corp.	500		12,258
Logitech International SA	138		8,009
NEC Corp.	500		19,205
Nomura Research Institute Ltd.	800		18,467
NTT Data Corp.	1,300		16,958
Otsuka Corp.	400		14,114
Ricoh Co. Ltd.	1,500		11,196
SCSK Corp.	800		11,659
Teleperformance	76		18,273
		$	221,047
Construction Materials — 1.78%
AGC, Inc.	400		14,837
Cie de Saint-Gobain	667		37,846
CRH PLC	592		29,838
Daikin Industries Ltd.	200		35,632

See accompanying notes.

17

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Construction Materials (continued)
Geberit AG	20	$	11,131
HeidelbergCement AG	222		16,193
Holcim AG (a)	755		48,603
Investment AB Latour, Class B	314		6,371
James Hardie Industries PLC, CDI (a)	369		7,851
Kingspan Group PLC	120		8,204
Nibe Industrier AB, Class B	1,735		19,692
Sika AG	59		16,476
West Fraser Timber Co. Ltd.	118		8,417
Xinyi Glass Holdings Ltd.	6,000		10,747
		$	271,838
Distribution/Wholesale — 1.62%
Bunzl PLC	537		20,251
D'ieteren Group (a)	31		6,015
IMCD NV	50		8,155
ITOCHU Corp.	1,400		45,350
Marubeni Corp.	2,100		28,398
Mitsubishi Corp.	1,100		39,361
Mitsui & Co. Ltd.	1,300		40,300
Sumitomo Corp.	1,700		29,973
Toromont Industries Ltd.	104		8,536
Toyota Tsusho Corp.	500		21,164
		$	247,503
Diversified Financial Services — 1.52%
abrdn PLC	2,329		5,847
AerCap Holdings NV (a)	129		7,254
Amundi SA (b)	200		12,591
ASX Ltd.	53		2,303
Brookfield Asset Management Ltd., Class A	233		7,632
Deutsche Boerse AG	178		34,641
Euronext NV (a),(b)	188		14,390
Futu Holdings Ltd., ADR (a)	230		11,925
IGM Financial, Inc.	339		10,131
Julius Baer Group Ltd.	255		17,369
London Stock Exchange Group PLC	50		4,853
Mitsubishi HC Capital, Inc.	2,600		13,394
Nomura Holdings, Inc.	5,400		20,730
ORIX Corp.	1,500		24,589
SBI Holdings, Inc.	700		13,834
Schroders PLC	1,214		6,889
Singapore Exchange Ltd.	1,400		9,889
TMX Group Ltd.	138		13,938
		$	232,199
Electric — 2.76%
BKW AG	122		19,174
Brookfield Renewable Corp., Class A	452		15,806
CLP Holdings Ltd.	528		3,814
E.ON SE	2,320		28,934
EDP - Energias de Portugal SA (a)	2,218		12,066
Elia Group SA	64		8,440
Emera, Inc.	229		9,407
Endesa SA	1,105		23,967
Enel SpA	3,804		23,214
Engie SA	1,922		30,378
Fortis, Inc.	316		13,433

See accompanying notes.

18

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Electric (continued)
Hydro One Ltd. (b)	614	$	17,482
Iberdrola SA (a)	4,752		59,188
Mercury NZ Ltd.	1,870		7,378
Meridian Energy Ltd.	2,425		7,961
National Grid PLC	1,826		24,699
Northland Power, Inc.	634		15,893
Origin Energy Ltd.	2,814		15,594
Orsted AS (b)	110		9,342
Power Assets Holdings Ltd.	500		2,682
Red Electrica Corp. SA	546		9,593
RWE AG	691		29,706
SSE PLC	686		15,258
Terna - Rete Elettrica Nazionale	1,357		11,135
Verbund AG	86		7,461
		$	422,005
Electrical Components & Equipment — 1.01%
ABB Ltd.	1,302		44,640
Legrand SA	292		26,626
Prysmian SpA	603		25,308
Schneider Electric SE	350		58,333
		$	154,907
Electronics — 0.90%
Assa Abloy AB, Class B	499		11,938
Halma PLC	293		8,057
Hirose Electric Co. Ltd.	100		13,007
Hoya Corp.	300		32,898
Ibiden Co. Ltd.	400		15,846
Murata Manufacturing Co. Ltd.	100		6,055
Shimadzu Corp.	545		16,993
TDK Corp.	700		24,911
Venture Corp. Ltd.	573		7,608
		$	137,313
Energy — Alternate Sources — 0.18%
Corp ACCIONA Energias Renovables SA (a)	335		12,992
Siemens Gamesa Renewable Energy SA (a)	87		1,703
Vestas Wind Systems A/S (a)	418		12,109
		$	26,804
Engineering & Construction — 1.68%
Acciona SA (a)	45		9,014
ACS Actividades de Construccion y Servicios SA	517		16,456
Aena SME SA (b)	52		8,397
Auckland International Airport Ltd. (a)	1,593		8,666
Bouygues SA	481		16,218
Cellnex Telecom SA (a),(b)	279		10,820
CK Infrastructure Holdings Ltd.	500		2,720
Eiffage SA	238		25,744
Ferrovial SA	396		11,634
Infrastrutture Wireless Italiane SpA (b)	964		12,671
Kajima Corp.	1,300		15,646
Keppel Corp. Ltd.	3,600		15,230
Skanska AB, Class B	411		6,278
Vinci SA	631		72,346

See accompanying notes.

19

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Engineering & Construction (continued)
WSP Global, Inc.	191	$	25,019
		$	256,859
Entertainment — 0.73%
Aristocrat Leisure Ltd.	476		11,836
Evolution AB (b)	173		23,139
Flutter Entertainment PLC (a)	139		25,273
Genting Singapore Ltd. (a)	10,000		8,416
La Francaise des Jeux SAEM (b)	359		14,947
Lottery Corp. Ltd.	2,538		8,686
Universal Music Group NV	751		18,981
		$	111,278
Environmental Control — 0.05%
GFL Environmental, Inc.	200		6,896
Food — 4.93%
Associated British Foods PLC	695		16,633
Barry Callebaut AG	4		8,477
Carrefour SA (a)	436		8,809
Chocoladefabriken Lindt & Spruengli AG	1		11,804
CK Hutchison Holdings Ltd.	2,500		15,510
Coles Group Ltd.	1,045		12,587
Danone SA	332		20,635
Empire Co. Ltd., Class A	616		16,513
George Weston Ltd.	204		27,034
J Sainsbury PLC	6,816		23,434
Jeronimo Martins SGPS SA (a)	736		17,257
Kerry Group PLC, Class A	31		3,088
Kesko Oyj, Class B	752		16,152
Koninklijke Ahold Delhaize NV	1,417		48,392
Loblaw Cos. Ltd.	216		19,685
MEIJI Holdings Co. Ltd.	600		14,257
Metro, Inc.	407		22,387
Mowi ASA	841		15,535
Nestle SA	2,432		296,268
Orkla ASA	2,151		15,257
Salmar ASA	146		6,356
Saputo, Inc.	325		8,409
Seven & i Holdings Co. Ltd.	900		40,501
Tesco PLC	4,829		15,828
WH Group Ltd. (b)	36,500		21,761
Woolworths Group Ltd.	1,233		31,237
		$	753,806
Food Service — 0.41%
Compass Group PLC	1,529		38,346
Sodexo SA	255		24,906
		$	63,252
Forest Products & Paper — 0.45%
Holmen AB, Class B	311		11,962
Mondi PLC	1,053		16,653
Oji Holdings Corp.	3,100		12,234
Smurfit Kappa Group PLC	434		15,687
UPM-Kymmene Oyj	366		12,285
		$	68,821

See accompanying notes.

20

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Gas — 0.54%
AltaGas Ltd.	899	$	14,987
Canadian Utilities Ltd., Class A	480		13,375
Enagas SA	456		8,753
Hong Kong & China Gas Co. Ltd.	3,250		2,861
Naturgy Energy Group SA	503		15,138
Snam SpA	2,060		10,922
Tokyo Gas Co. Ltd.	900		16,919
		$	82,955
Hand/Machine Tools — 0.48%
Disco Corp.	300		34,570
Fuji Electric Co. Ltd.	400		15,666
Schindler Holding AG	31		6,847
Schindler Holding AG	28		5,906
Techtronic Industries Co. Ltd.	1,000		10,809
		$	73,798
Healthcare — Products — 1.20%
Alcon, Inc.	68		4,808
Carl Zeiss Meditec AG	48		6,663
Cochlear Ltd.	115		18,195
Coloplast A/S, Class B	96		12,603
Demant A/S (a)	175		6,119
DiaSorin SpA	54		5,684
EBOS Group Ltd.	487		14,160
EssilorLuxottica SA	136		24,484
Fisher & Paykel Healthcare Corp. Ltd.	448		7,465
Lifco AB, Class B	343		7,370
Olympus Corp.	1,500		26,193
QIAGEN NV (a)	230		10,454
Sartorius Stedim Biotech	23		7,034
Siemens Healthineers AG (b)	174		10,005
Smith & Nephew PLC	197		2,727
Sonova Holding AG	34		9,981
Straumann Holding AG	69		10,283
		$	184,228
Healthcare — Services — 0.59%
BioMerieux (a)	129		13,570
Eurofins Scientific SE	118		7,888
Fresenius Medical Care AG & Co. KGaA	192		8,142
Fresenius SE & Co. KGaA	318		8,570
Lonza Group AG	29		17,350
Medibank Pvt Ltd.	7,106		15,960
Ramsay Health Care Ltd.	53		2,358
Sonic Healthcare Ltd.	713		16,605
		$	90,443
Holding Companies — Diversified — 0.22%
Jardine Matheson Holdings Ltd.	383		18,603
Swire Pacific Ltd., Class A	2,000		15,363
		$	33,966
Home Builders — 0.67%
Barratt Developments PLC	1,216		6,998
Berkeley Group Holdings PLC	118		6,109
Daiwa House Industry Co. Ltd.	900		21,108

See accompanying notes.

21

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Home Builders (continued)
Iida Group Holdings Co. Ltd.	700	$	11,383
Open House Group Co. Ltd.	300		11,184
Persimmon PLC	436		6,755
Sekisui Chemical Co. Ltd.	800		11,303
Sekisui House Ltd.	1,000		20,320
Taylor Wimpey PLC	4,706		6,906
		$	102,066
Home Furnishings — 0.73%
Rational AG	8		5,353
SEB SA	56		6,365
Sony Group Corp.	1,100		99,292
		$	111,010
Household Products — 1.61%
Beiersdorf AG	86		11,187
Essity AB, Class B	420		11,994
Haleon PLC	3,198		12,703
L'Oreal SA	175		78,050
Unilever PLC	2,545		131,546
		$	245,480
Household Products/Wares — 0.36%
Henkel AG & Co. KGaA	127		9,228
Reckitt Benckiser Group PLC	598		45,427
		$	54,655
Insurance — 4.78%
Aegon NV	1,743		7,469
Ageas SA	220		9,510
AIA Group Ltd.	10,600		111,605
Allianz SE	295		68,081
Assicurazioni Generali SpA	1,269		25,295
AXA SA	1,568		47,894
Baloise Holding AG	62		9,649
Fairfax Financial Holdings Ltd.	35		23,277
Gjensidige Forsikring ASA	92		1,505
Great-West Lifeco, Inc.	891		23,615
Hannover Rueck SE	139		27,187
iA Financial Corp., Inc.	281		17,810
Insurance Australia Group Ltd.	2,886		9,048
Intact Financial Corp.	251		35,922
Japan Post Holdings Co. Ltd.	2,900		23,512
Manulife Financial Corp.	2,571		47,178
Muenchener Rueckversicherungs-Gesellschaft AG in Muenchen	69		24,133
NN Group NV	288		10,451
Phoenix Group Holdings PLC	298		2,009
Power Corp. of Canada	486		12,421
Prudential PLC	1,049		14,260
QBE Insurance Group Ltd.	1,862		18,159
Sampo Oyj, Class A	787		37,110
Sun Life Financial, Inc.	421		19,668
Suncorp Group Ltd.	2,256		18,262
Swiss Life Holding AG	23		14,158
Swiss Re AG	306		31,384
Tokio Marine Holdings, Inc.	1,600		30,693
Tryg A/S	106		2,313

See accompanying notes.

22

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Insurance (continued)
Zurich Insurance Group AG	17	$	8,133
		$	731,711
Internet — 1.01%
Adevinta ASA (a)	781		5,539
Auto Trader Group PLC (b)	1,276		9,699
Delivery Hero SE (a),(b)	183		6,226
Prosus NV (a)	543		42,364
Scout24 SE (b)	105		6,229
SEEK Ltd.	406		6,492
Shopify, Inc., Class A (a)	1,000		47,947
United Internet AG	609		10,481
Wix.com Ltd. (a)	61		6,088
ZOZO, Inc.	600		13,624
		$	154,689
Investment Companies — 0.37%
EXOR NV (a)	30		2,467
Groupe Bruxelles Lambert NV	29		2,469
Industrivarden AB, Class A	209		5,632
Industrivarden AB, Class C	215		5,784
Melrose Industries PLC	3,351		6,883
Washington H Soul Pattinson & Co. Ltd.	1,017		20,530
Wendel SE (a)	125		13,197
		$	56,962
Iron & Steel — 0.89%
ArcelorMittal SA (a)	327		9,883
BlueScope Steel Ltd.	530		7,139
Fortescue Metals Group Ltd.	2,495		37,508
JFE Holdings, Inc.	1,400		17,704
Mineral Resources Ltd.	279		15,030
Nippon Steel Corp.	1,300		30,548
voestalpine AG	561		19,031
		$	136,843
Leisure Time — 0.37%
BRP, Inc.	273		21,363
Shimano, Inc.	100		17,202
Yamaha Motor Co. Ltd.	700		18,242
		$	56,807
Lodging — 0.39%
Accor SA (a)	215		6,988
City Developments Ltd.	2,300		12,737
Galaxy Entertainment Group Ltd. (a)	1,000		6,682
InterContinental Hotels Group PLC	161		10,550
Sands China Ltd. (a)	2,400		8,347
Whitbread PLC	375		13,818
		$	59,122
Machinery — Construction & Mining — 1.09%
Epiroc AB, Class A	465		9,220
Epiroc AB, Class B	428		7,276
Hitachi Construction Machinery Co. Ltd.	600		13,896
Hitachi Ltd.	900		49,157
Komatsu Ltd.	1,300		32,085

See accompanying notes.

23

Schedule of Investments
Principal International Adaptive Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Machinery — Construction & Mining (continued)
Metso Outotec Oyj	1,303	$	14,188
Mitsubishi Heavy Industries Ltd.	600		22,034
Sandvik AB	502		10,631
Siemens Energy AG (a)	377		8,275
		$	166,762
Machinery — Diversified — 1.25%
Atlas Copco AB, Class A	1,170		14,828
Atlas Copco AB, Class B	1,750		20,095
CNH Industrial NV	1,305		19,927
GEA Group AG	358		16,287
Keyence Corp.	200		97,082
Kone Oyj, Class B	175		9,110
Spirax-Sarco Engineering PLC	57		8,336
Wartsila OYJ Abp	636		5,992
		$	191,657
Media — 0.88%
Bollore SE	2,414		14,896
Informa PLC	1,276		10,902
Pearson PLC	1,508		15,708
Quebecor, Inc., Class B	917		22,669
Shaw Communications, Inc., Class B	639		19,121
Thomson Reuters Corp.	127		16,524
Vivendi SE	222		2,239
Wolters Kluwer NV	255		32,176
		$	134,235
Metal Fabrication & Hardware — 0.35%
Norsk Hydro ASA	2,259		16,786
SKF AB, Class B	366		7,194
Tenaris SA	1,452		20,629
VAT Group AG (b)	23		8,250
		$	52,859
Mining — 2.68%
Anglo American PLC	506		16,716
Antofagasta PLC	387		7,548
BHP Group Ltd.	4,480		141,438
Boliden AB	426		16,738
First Quantum Minerals Ltd.	477		10,966
Franco-Nevada Corp.	117		17,066
Glencore PLC (a)	7,413		42,486
IGO Ltd.	803		6,854
Lundin Mining Corp.	1,089		7,397
Northern Star Resources Ltd.	931		7,661
Pilbara Minerals Ltd.	8,035		21,162
Rio Tinto Ltd.	329		26,421
Rio Tinto PLC	380		25,679
South32 Ltd.	6,286		18,362
Sumitomo Metal Mining Co. Ltd.	500		19,013
Teck Resources Ltd., Class B	329		12,013
Wheaton Precious Metals Corp.	259		12,474
		$	409,994
Miscellaneous Manufacturers — 0.62%
Alfa Laval AB	210		7,480

See accompanying notes.

24

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Miscellaneous Manufacturers (continued)
Alstom SA	256	$	6,963
Indutrade AB	337		7,146
Knorr-Bremse AG	95		6,314
Orica Ltd.	848		8,724
Siemens AG	300		48,562
Smiths Group PLC	428		9,063
		$	94,252
Office & Business Equipment — 0.09%
Seiko Epson Corp.	1,000		14,167
Oil & Gas — 5.70%
Aker BP ASA	623		15,251
Ampol Ltd.	1,042		21,237
ARC Resources Ltd.	1,317		14,939
BP PLC	16,046		101,109
Canadian Natural Resources Ltd.	774		42,832
Cenovus Energy, Inc.	1,510		26,345
DCC PLC	162		9,429
Eni SpA	3,103		43,431
Equinor ASA	899		25,648
Galp Energia SGPS SA (a)	1,182		13,408
Idemitsu Kosan Co. Ltd.	600		13,105
Imperial Oil Ltd.	382		19,426
Inpex Corp.	1,700		17,887
Neste Oyj	213		10,494
OMV AG	462		21,174
Parkland Corp.	575		13,785
Repsol SA	2,129		32,752
Santos Ltd.	3,992		18,412
Shell PLC	6,241		177,729
Suncor Energy, Inc.	1,118		34,711
TotalEnergies SE	2,200		129,698
Tourmaline Oil Corp.	479		19,961
Woodside Energy Group Ltd.	2,215		49,364
		$	872,127
Oil & Gas Services — 0.04%
Sembcorp Marine Ltd. (a)	71,127		6,360
Packaging & Containers — 0.21%
CCL Industries, Inc., Class B	514		25,534
Stora Enso Oyj, Class R	550		7,146
		$	32,680
Pharmaceuticals — 7.60%
Amplifon SpA	205		7,101
Astellas Pharma, Inc.	100		1,418
AstraZeneca PLC	1,371		189,963
Bayer AG	698		44,450
Chugai Pharmaceutical Co. Ltd.	1,000		24,628
Daiichi Sankyo Co. Ltd.	1,600		58,107
GSK PLC	3,224		56,833
Hikma Pharmaceuticals PLC	395		8,162
Ipsen SA (a)	162		17,832
Merck KGaA	62		11,535
Nippon Shinyaku Co. Ltd.	300		13,173
Novartis AG	985		90,173
Novo Nordisk A/S, Class B	1,464		231,406

See accompanying notes.

25

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Pharmaceuticals (continued)
Ono Pharmaceutical Co. Ltd.	800	$	16,654
Orion Oyj, Class B	317		14,161
Recordati Industria Chimica e Farmaceutica SpA	200		8,450
Roche Holding AG	33		9,919
Roche Holding AG	622		177,399
Sanofi	872		94,795
Shionogi & Co. Ltd.	500		22,508
Takeda Pharmaceutical Co. Ltd.	1,400		45,867
Teva Pharmaceutical Industries Ltd., ADR (a)	1,765		15,620
UCB SA (a)	30		2,682
		$	1,162,836
Pipelines — 0.36%
APA Group	1,454		9,836
Enbridge, Inc.	261		9,951
Keyera Corp.	99		2,168
Pembina Pipeline Corp.	811		26,271
TC Energy Corp.	184		7,157
		$	55,383
Private Equity — 0.50%
3i Group PLC	1,026		21,327
Brookfield Corp.	553		18,016
Capitaland Investment Ltd.	5,800		16,038
EQT AB	368		7,467
Eurazeo SE	181		12,857
		$	75,705
Real Estate — 1.24%
Aroundtown SA (a)	3,471		4,943
Azrieli Group Ltd.	135		7,726
CK Asset Holdings Ltd.	2,000		12,140
Fastighets AB Balder, Classs B (a)	3,090		12,656
FirstService Corp.	111		15,640
Hang Lung Properties Ltd.	2,000		3,740
Henderson Land Development Co. Ltd.	1,000		3,459
Hongkong Land Holdings Ltd.	516		2,265
Hulic Co. Ltd.	1,600		13,099
LEG Immobilien SE (a)	114		6,241
Mitsui Fudosan Co. Ltd.	1,300		24,321
Nomura Real Estate Holdings, Inc.	500		11,034
REA Group Ltd.	74		6,828
Sagax AB, Class B	299		6,879
Sino Land Co. Ltd.	6,000		8,117
Sun Hung Kai Properties Ltd.	1,000		14,013
Swire Properties Ltd.	5,200		13,381
Swiss Prime Site AG	26		2,161
UOL Group Ltd.	2,800		14,581
Wharf Real Estate Investment Co. Ltd.	1,000		5,745
		$	188,969
REITs — 1.13%
British Land Co. PLC	2,793		13,361
Canadian Apartment Properties REIT	70		2,456
CapitaLand Ascendas REIT	7,600		16,333
CapitaLand Integrated Commercial Trust	6,517		9,696
Dexus	1,711		8,589
Gecina SA	57		5,907

See accompanying notes.

26

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
REITs (continued)
Goodman Group	879	$	11,040
GPT Group	728		2,063
Klepierre SA (a)	857		19,378
Land Securities Group PLC	932		7,142
Link REIT	1,540		9,907
Mapletree Logistics Trust	6,200		7,967
Mapletree Pan Asia Commercial Trust	6,100		8,251
Mirvac Group	6,229		8,661
RioCan Real Estate Investment Trust	144		2,172
Scentre Group	1,313		2,414
Stockland	6,329		16,838
Vicinity Ltd.	6,239		8,112
Warehouses De Pauw CVA	441		13,066
		$	173,353
Retail — 2.85%
Alimentation Couche-Tard, Inc.	756		38,010
Canadian Tire Corp. Ltd., Class A	129		16,834
Cie Financiere Richemont SA, Class A	170		27,109
Dollarama, Inc.	346		20,678
Fast Retailing Co. Ltd.	200		43,502
H & M Hennes & Mauritz AB, Class B	650		9,257
Industria de Diseno Textil SA	878		29,423
Jardine Cycle & Carriage Ltd.	800		18,804
JD Sports Fashion PLC	9,607		21,065
Kingfisher PLC	4,070		13,114
Mercedes-Benz Finance North America LLC	300		15,839
Moncler SpA	257		17,710
Next PLC	286		23,187
Pan Pacific International Holdings Corp.	800		15,418
Pandora A/S	240		22,898
Reece Ltd.	555		6,437
Restaurant Brands International, Inc.	352		23,631
Swatch Group AG	46		15,756
Swatch Group AG	193		12,192
USS Co. Ltd.	800		13,828
Welcia Holdings Co. Ltd.	600		12,807
Wesfarmers Ltd.	568		19,079
		$	436,578
Semiconductors — 3.14%
Advantest Corp.	300		27,475
ASM International NV	51		20,569
ASML Holding NV	357		242,056
Hamamatsu Photonics KK	300		16,065
Infineon Technologies AG	943		38,535
Renesas Electronics Corp. (a)	1,700		24,500
Rohm Co. Ltd.	200		16,524
STMicroelectronics NV	554		29,413
SUMCO Corp.	1,100		16,412
Tokyo Electron Ltd.	300		36,242
Tower Semiconductor Ltd. (a)	301		12,806
		$	480,597
Shipbuilding — 0.08%
Kongsberg Gruppen ASA	302		12,196

See accompanying notes.

27

	Schedule of Investments
Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Software — 1.43%
Constellation Software, Inc.	19	$	35,721
Dassault Systemes SE	299		12,282
Descartes Systems Group, Inc. (a)	200		16,142
Nemetschek SE	100		6,863
Open Text Corp.	267		10,299
Oracle Corp. Japan	200		14,355
Sage Group PLC	1,051		10,048
SAP SE	544		68,472
Square Enix Holdings Co. Ltd.	300		14,370
TIS, Inc.	600		15,771
WiseTech Global Ltd.	316		13,759
		$	218,082
Telecommunications — 3.73%
BCE, Inc.	158		7,078
Bezeq The Israeli Telecommunication Corp. Ltd.	10,150		13,791
BT Group PLC	4,903		8,818
Deutsche Telekom AG	3,588		86,968
Elisa Oyj	277		16,691
Hikari Tsushin, Inc.	100		13,986
HKT Trust & HKT Ltd.	7,000		9,292
KDDI Corp.	1,400		43,157
Koninklijke KPN NV	5,323		18,796
Nice Ltd. (a)	38		8,508
Nippon Telegraph & Telephone Corp.	1,400		41,776
Nokia Oyj	5,134		25,141
Orange SA	3,177		37,735
Rogers Communications, Inc., Class B	53		2,456
Singapore Telecommunications Ltd.	1,600		2,958
SoftBank Corp.	3,500		40,305
SoftBank Group Corp.	1,100		42,931
Spark New Zealand Ltd.	6,902		21,838
Swisscom AG	20		12,748
Tele2 AB, Class B	911		9,063
Telecom Italia SpA (a)	18,290		6,034
Telefonaktiebolaget LM Ericsson, Class B	1,725		10,072
Telefonica Deutschland Holding AG	4,435		13,645
Telefonica SA	6,054		26,085
Telenor ASA	832		9,751
Telia Co. AB	857		2,177
Telstra Group Ltd.	6,516		18,381
TELUS Corp.	131		2,601
Vodafone Group PLC	15,477		17,049
		$	569,831
Toys, Games & Hobbies — 0.38%
Bandai Namco Holdings, Inc.	900		19,308
Nintendo Co. Ltd.	1,000		38,645
		$	57,953
Transportation — 2.24%
AP Moller - Maersk A/S, Class B	7		12,682
AP Moller - Maersk A/S, Class A	7		12,391
Aurizon Holdings Ltd.	3,688		8,283
Canadian National Railway Co.	254		29,971
Canadian Pacific Railway Ltd.	115		8,855
Deutsche Post AG	763		35,656
DSV A/S	228		44,028

See accompanying notes.

28

		Schedule of Investments
	Principal International Adaptive Multi-Factor ETF
		March 31, 2023 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Transportation (continued)
Getlink SE (a)		587	$	9,670
Kintetsu Group Holdings Co. Ltd.		400		12,849
Kuehne + Nagel International AG		68		20,208
Mitsui OSK Lines Ltd.		700		17,451
MTR Corp. Ltd.		500		2,411
NIPPON EXPRESS HOLDINGS, Inc.		300		18,008
Nippon Yusen KK		900		20,938
Poste Italiane SpA (b)		2,085		21,282
SG Holdings Co. Ltd.		1,000		14,762
SITC International Holdings Co. Ltd.		5,000		10,739
TFI International, Inc.		239		28,519
Yamato Holdings Co. Ltd.		800		13,671
		$		342,374
Water — 0.17%
Severn Trent PLC		70		2,486
United Utilities Group PLC		183		2,393
Veolia Environnement SA		690		21,252
		$		26,131
TOTAL COMMON STOCKS		$		14,953,078
PREFERRED STOCKS — 0.45%		Shares Held		Value
Auto Manufacturers — 0.28%
Bayerische Motoren Werke AG
	6.18%	224	$	22,908
Porsche Automobil Holding SE
	4.84%	128		7,346
Volkswagen AG
	21.22%	89		12,127
		$		42,381
Electronics — 0.10%
Sartorius AG
	0.37%	35		14,690
Household Products/Wares — 0.07%
Henkel AG & Co. KGaA
	2.58%	148		11,566
TOTAL PREFERRED STOCKS		$		68,637
INVESTMENT COMPANIES — 0.42%		Shares Held		Value
Money Market Fund — 0.42%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (c)		64,624	$	64,624
TOTAL INVESTMENT COMPANIES		$		64,624
Total Investments		$		15,086,339
Other Assets and Liabilities — 1.36%				207,753
Total Net Assets — 100.00%		$		15,294,092
(a)	Non-income producing security.
(b)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $249,082 or 1.63% of net assets.
(c)	Current yield shown is as of period end.
See accompanying notes.		29

	Schedule of Investments
	Principal International Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
	Portfolio Summary
Location	Percent
Japan	19.06	%
United Kingdom	11.96	%
France	10.81	%
Canada	9.85	%
Switzerland	7.69	%
Germany	6.95	%
Australia	6.60	%
Netherlands	4.40	%
Denmark	2.79	%
Spain	2.70	%
Sweden	2.45	%
Hong Kong	2.33	%
Italy	2.13	%
Singapore	1.76	%
Finland	1.19	%
Israel	1.12	%
Ireland	1.02	%
Norway	0.99	%
Belgium	0.83	%
United States	0.53	%
Austria	0.42	%
New Zealand	0.35	%
Luxemburg	0.28	%
Portugal	0.28	%
Mongolia	0.05	%
Jordan	0.05	%
Chile	0.05	%
Other Assets and Liabilities	1.36	%
TOTAL NET ASSETS	100.00	%

See accompanying notes.

30

	Schedule of Investments
	Principal Investment Grade Corporate Active ETF
	March 31, 2023 (unaudited)
		Principal
BONDS — 89.79%		Amount		Value
Aerospace & Defense — 3.43%
Boeing Co.
3.25%, 02/01/2028	$	357,000	$	332,656
5.71%, 05/01/2040		307,000		310,564
Lockheed Martin Corp.
5.70%, 11/15/2054		152,000		173,091
Raytheon Technologies Corp.
4.13%, 11/16/2028		593,000		584,471
			$	1,400,782
Airlines — 7.82%
Delta Air Lines, Inc./SkyMiles IP Ltd.
4.75%, 10/20/2028 (a)		1,049,262		1,012,026
Southwest Airlines Co.
5.25%, 05/04/2025		1,096,000		1,095,111
United Airlines 2016-2 Class A Pass Through Trust
3.10%, 10/07/2028		1,256,559		1,086,303
			$	3,193,440
Auto Manufacturers — 0.49%
Mercedes-Benz Finance North America LLC
4.80%, 04/07/2030		200,000		200,589
Banks — 23.24%
Bank of America Corp.
(6-month Secured Overnight Financing Rate + 1.06%),
2.09%, 06/14/2029 (b)		703,000		605,432
(5-year Treasury Constant Maturity Rate + 1.20%),
2.48%, 09/21/2036 (b)		624,000		473,882
(6-month Secured Overnight Financing Rate + 1.88%),
2.83%, 10/24/2051 (b)		343,000		223,649
(6-month Secured Overnight Financing Rate + 1.99%),
6.20%, 11/10/2028 (b)		355,000		371,111
Citigroup, Inc.
(6-month Secured Overnight Financing Rate + 1.94%),
3.79%, 03/17/2033 (b)		655,000		587,081
(6-month Secured Overnight Financing Rate + 1.54%),
5.61%, 09/29/2026 (b)		662,000		666,934
(6-month Secured Overnight Financing Rate + 2.33%),
6.27%, 11/17/2033 (b)		108,000		116,802
Deutsche Bank AG
(6-month U.S. International Swaps and Derivative Association + 2.55%),
4.88%, 12/01/2032 (b)		464,000		376,939
First Republic Bank
4.63%, 02/13/2047		544,000		299,200
Goldman Sachs Group, Inc.
(6-month Secured Overnight Financing Rate + 1.41%),
3.10%, 02/24/2033 (b)		850,000		729,955
JPMorgan Chase & Co.
(3-month Term Secured Overnight Financing Rate + 0.70%),
1.04%, 02/04/2027 (b)		853,000		761,390
(6-month Secured Overnight Financing Rate + 2.08%),
4.91%, 07/25/2033 (b)		385,000		382,669
Morgan Stanley
(6-month Secured Overnight Financing Rate + 1.43%),
2.80%, 01/25/2052 (b)		545,000		359,251
(3-month USD LIBOR + 1.34%),
3.59%, 07/22/2028 (b)		308,000		290,927

See accompanying notes.

31

Schedule of Investments
Principal Investment Grade Corporate Active ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
Morgan Stanley (continued)
5.00%, 11/24/2025	$	269,000	$	266,660
National Australia Bank Ltd.
2.33%, 08/21/2030 (a)		900,000		702,713
State Street Corp.
(6-month Secured Overnight Financing Rate + 1.57%),
4.82%, 01/26/2034 (b)		83,000		82,542
Truist Financial Corp.
(6-month Secured Overnight Financing Rate + 1.63%),
5.90%, 10/28/2026 (b)		195,000		194,400
UBS Group AG
(1-year Treasury Constant Maturity Rate + 1.75%),
4.75%, 05/12/2028 (a),(b)		667,000		639,461
Wells Fargo & Co.
(6-month Secured Overnight Financing Rate + 2.10%),
2.39%, 06/02/2028 (b)		930,000		837,427
Westpac Banking Corp.
(1-year Treasury Constant Maturity Rate + 2.68%),
5.41%, 08/10/2033 (b)		548,000		523,707
			$	9,492,132
Beverages — 2.57%
Anheuser-Busch InBev Worldwide, Inc.
4.38%, 04/15/2038		465,000		441,559
4.90%, 01/23/2031		386,000		397,677
PepsiCo, Inc.
4.45%, 02/15/2033 (c)		205,000		210,409
			$	1,049,645
Biotechnology — 0.56%
Amgen, Inc.
5.25%, 03/02/2030		138,000		141,144
5.60%, 03/02/2043		84,000		86,545
			$	227,689
Commercial Services — 1.11%
CoStar Group, Inc.
2.80%, 07/15/2030 (a)		539,000		451,625
Computers — 0.79%
Apple, Inc.
3.95%, 08/08/2052		360,000		322,411
Diversified Financial Services — 1.00%
AerCap Ireland Capital DAC/AerCap Global Aviation Trust
3.00%, 10/29/2028		270,000		235,716
3.85%, 10/29/2041		790		604
Blackstone Holdings Finance Co. LLC
2.85%, 08/05/2051 (a)		298,342		171,399
			$	407,719
Electric — 7.62%
Commonwealth Edison Co.
4.00%, 03/01/2049		391,000		326,940
FirstEnergy Corp.
5.10%, 07/15/2047		226,000		200,445

See accompanying notes.

32

	Schedule of Investments
	Principal Investment Grade Corporate Active ETF
	March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Electric (continued)
Florida Power & Light Co.
3.95%, 03/01/2048	$	226,000	$	194,503
Louisville Gas & Electric Co
5.45%, 04/15/2033		109,000		113,273
Monongahela Power Co.
3.55%, 05/15/2027 (a)		242,000		229,735
NRG Energy, Inc.
2.00%, 12/02/2025 (a)		306,000		275,565
Pacific Gas & Electric Co.
1.70%, 11/15/2023		470,000		458,467
2.95%, 03/01/2026		589,000		547,896
WEC Energy Group, Inc.
1.38%, 10/15/2027		619,000		536,678
5.00%, 09/27/2025		229,000		229,060
			$	3,112,562
Environmental Control — 1.56%
Waste Connections, Inc.
4.20%, 01/15/2033		430,000		412,687
Waste Management, Inc.
4.63%, 02/15/2030		226,000		226,122
			$	638,809
Food — 2.69%
JBS USA LUX SA/JBS USA Food Co./JBS USA Finance, Inc.
4.38%, 02/02/2052 (a)		347,000		250,769
Kraft Heinz Foods Co.
4.88%, 10/01/2049		313,000		290,826
Mars, Inc.
2.38%, 07/16/2040 (a)		272,000		196,265
Pilgrim's Pride Corp.
3.50%, 03/01/2032		445,000		362,141
Sysco Corp.
3.15%, 12/14/2051		736		514
			$	1,100,515
Gas — 1.78%
NiSource, Inc.
0.95%, 08/15/2025		750,000		682,310
5.25%, 03/30/2028		45,000		45,776
			$	728,086
Healthcare — Products — 1.35%
Boston Scientific Corp.
2.65%, 06/01/2030		623,000		550,455
Healthcare — Services — 2.33%
Centene Corp.
2.45%, 07/15/2028		672,000		584,640
UnitedHealth Group, Inc.
2.75%, 05/15/2040		316,000		238,987
5.88%, 02/15/2053		113,000		127,011
			$	950,638

See accompanying notes.

33

	Schedule of Investments
	Principal Investment Grade Corporate Active ETF
	March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Insurance — 4.16%
Arthur J Gallagher & Co.
2.40%, 11/09/2031	$	379,000	$	307,804
5.50%, 03/02/2033		158,000		161,417
Chubb INA Holdings, Inc.
3.35%, 05/03/2026		315,000		304,653
Corebridge Financial, Inc.
4.40%, 04/05/2052 (a)		226,000		176,785
Everest Reinsurance Holdings, Inc.
3.13%, 10/15/2052		278,000		187,542
Markel Corp.
4.30%, 11/01/2047		275,000		225,853
MetLife, Inc.
5.00%, 07/15/2052		149,000		139,396
New York Life Insurance Co.
3.75%, 05/15/2050 (a)		242,000		195,160
			$	1,698,610
Internet — 1.63%
Amazon.com, Inc.
4.55%, 12/01/2027		655,000		664,892
Media — 1.47%
Charter Communications Operating LLC/Charter Communications Operating
Capital
2.30%, 02/01/2032		395,000		300,966
Comcast Corp.
3.97%, 11/01/2047		355,000		298,421
			$	599,387
Mining — 1.63%
Yamana Gold, Inc.
2.63%, 08/15/2031		826,000		664,561
Pharmaceuticals — 7.89%
AbbVie, Inc.
3.20%, 11/21/2029		318,000		295,110
4.05%, 11/21/2039		466,000		416,247
Astrazeneca Finance LLC
4.88%, 03/03/2033		106,000		109,341
Bayer U.S. Finance II LLC
4.63%, 06/25/2038 (a)		513,000		469,785
Becton Dickinson & Co.
3.70%, 06/06/2027		817,000		789,349
Bristol-Myers Squibb Co.
4.13%, 06/15/2039		226,000		210,370
CVS Health Corp.
5.13%, 02/21/2030		205,000		207,808
Eli Lilly & Co.
4.70%, 02/27/2033		158,000		161,992
Zoetis, Inc.
3.90%, 08/20/2028		579,000		563,293
			$	3,223,295
Pipelines — 2.13%
Energy Transfer LP
3.75%, 05/15/2030		399,000		368,202
5.15%, 03/15/2045		266,000		231,571

See accompanying notes.

34

		Schedule of Investments
		Principal Investment Grade Corporate Active ETF
		March 31, 2023 (unaudited)
			Principal
BONDS (continued)			Amount		Value
Pipelines (continued)
Sabine Pass Liquefaction LLC
5.00%, 03/15/2027		$	271,000	$	270,027
				$	869,800
REITs — 2.42%
Invitation Homes Operating Partnership LP
2.00%, 08/15/2031			435,000		333,669
Kimco Realty OP LLC
3.20%, 04/01/2032			435,000		365,646
Realty Income Corp.
3.10%, 12/15/2029			70		63
Spirit Realty LP
3.20%, 02/15/2031			345,000		287,218
				$	986,596
Semiconductors — 0.66%
Broadcom, Inc.
4.11%, 09/15/2028			280,000		267,551
Software — 4.32%
Fiserv, Inc.
4.40%, 07/01/2049			273,000		233,245
Oracle Corp.
2.80%, 04/01/2027			226,000		210,122
4.00%, 07/15/2046			226,000		172,428
6.15%, 11/09/2029			120,000		127,815
Take-Two Interactive Software, Inc.
4.00%, 04/14/2032			357,000		328,006
VMware, Inc.
4.65%, 05/15/2027			705,000		694,108
				$	1,765,724
Telecommunications — 3.69%
AT&T, Inc.
3.50%, 09/15/2053			749,000		543,810
T-Mobile USA, Inc.
3.38%, 04/15/2029			1,058,000		964,565
				$	1,508,375
Transportation — 0.59%
United Parcel Service, Inc.
4.88%, 03/03/2033			236,000		242,196
Water — 0.86%
Essential Utilities, Inc.
2.40%, 05/01/2031			421,000		350,618
TOTAL BONDS				$	36,668,702
U.S. GOVERNMENT & GOVERNMENT AGENCY OBLIGATIONS —			Principal
2.86	%		Amount		Value
U.S. Treasury — 2.86%
3.00%, 08/15/2052		$	201,800	$	177,269
4.13%, 11/15/2032			942,800		990,676
TOTAL U.S. GOVERNMENT & GOVERNMENT AGENCY OBLIGATIONS				$	1,167,945
See accompanying notes.		35

		Schedule of Investments
	Principal Investment Grade Corporate Active ETF
		March 31, 2023 (unaudited)
INVESTMENT COMPANIES — 6.43%				Shares Held		Value
Money Market Funds — 6.43%
Principal Government Money Market Fund — Class R-6 4.72% (d),(e),(f)				160,268	$	160,268
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (f)				2,465,081		2,465,081
TOTAL INVESTMENT COMPANIES				$		2,625,349
Total Investments				$		40,461,996
Other Assets and Liabilities — 0.92%						376,115
Total Net Assets — 100.00%				$		40,838,111
(a)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $4,771,288 or 11.68% of net assets.
(b)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or
	floating rate in the future.
(c)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $157,768 or
	0.39% of net assets.
(d)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(e)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $160,268 or 0.39% of net assets.
(f)	Current yield shown is as of period end.
	Portfolio Summary
Sector		Percent
Financial		30.81	%
Consumer, Non-cyclical		18.50	%
Utilities		10.26	%
Consumer, Cyclical		8.31	%
Communications		6.79	%
Money Market Funds		6.43	%
Technology		5.77	%
Industrial		5.59	%
Government		2.86	%
Energy		2.13	%
Basic Materials		1.63	%
Other Assets and Liabilities		0.92	%
TOTAL NET ASSETS		100.00	%
See accompanying notes.		36

			Schedule of Investments
		Principal Investment Grade Corporate Active ETF
			March 31, 2023 (unaudited)
			June 30, 2022	Purchases				Sales		March 31, 2023
Affiliated Securities			Value		Cost	Proceeds				Value
Principal Government Money
Market Fund — Class R-6 4.72%		$	—	$	3,414,280	$		3,254,012	$	160,268
Principal Government Money
Market Fund — Institutional Class
4.67	%		1,398,980		3,608,665			5,007,645		—
		$	1,398,980	$	7,022,945	$		8,261,657	$	160,268
						Realized Gain
					Realized			from		Change in
				Gain/(Loss) on		Capital Gain				Unrealized
			Income (a)	Investments		Distributions				Gain/(Loss)
Principal Government Money
Market Fund — Class R-6 4.72%		$	—	$	—	$		—	$	—
Principal Government Money
Market Fund — Institutional Class
4.67	%		—		—			—		—
		$	—	$	—	$		—	$	—
(a) Amount excludes earnings from securities lending collateral.
			Futures Contracts
										Value and Unrealized
								Notional		Appreciation/
Description and Expiration Date			Type		Contracts			Amount		(Depreciation)
U.S. 10 Year Ultra; June 2023			Short			6	$	727,488	$	644
U.S. 5 Year CBT; June 2023			Short			7		747,674		(18,881	)
U.S. Long Bond CBT; June 2023			Long			12		1,537,479		36,396
U.S. Ultra Bond CBT; June 2023			Long			13		1,749,122		85,503
Total									$	103,662
See accompanying notes.				37

	Schedule of Investments
	Principal Millennial Global Growth ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 99.20%	Shares Held		Value
Apparel — 6.07%
adidas AG	605	$	106,804
Carter's, Inc.	690		49,625
Columbia Sportswear Co.	702		63,348
Fila Holdings Corp.	2,452		68,747
Gildan Activewear, Inc.	1,788		59,402
Kering SA	226		147,058
Levi Strauss & Co., Class A	3,207		58,464
LVMH Moet Hennessy Louis Vuitton SE	199		182,235
NIKE, Inc., Class B	972		119,206
PVH Corp.	826		73,646
Ralph Lauren Corp.	559		65,218
SMCP SA (a),(b)	9,031		80,263
Torrid Holdings, Inc. (a),(c)	10,459		45,601
Urban Outfitters, Inc. (a)	23,408		648,870
VF Corp.	2,296		52,601
		$	1,821,088
Beverages — 1.84%
Brown-Forman Corp., Class B	1,978		127,126
Constellation Brands, Inc., Class A	578		130,565
Fevertree Drinks PLC	2,940		46,568
Monster Beverage Corp. (a)	3,326		179,637
Treasury Wine Estates Ltd.	7,978		69,701
		$	553,597
Commercial Services — 2.51%
Aaron's Co., Inc.	3,155		30,477
Adyen NV (a),(b)	284		449,431
Global Payments, Inc.	961		101,136
GMO Payment Gateway, Inc.	600		51,425
Nuvei Corp. (a),(b),(c)	920		40,043
Paysafe Ltd. (a)	1,706		29,462
PROG Holdings, Inc. (a)	2,201		52,362
		$	754,336
Computers — 0.42%
Apple, Inc.	757		124,829
Construction Materials — 1.00%
Fortune Brands Innovations, Inc.	1,779		104,481
Masco Corp.	2,599		129,222
Masterbrand, Inc. (a)	1,779		14,303
Mohawk Industries, Inc. (a)	510		51,112
		$	299,118
Diversified Financial Services — 7.90%
Coinbase Global, Inc., Class A (a)	4,094		276,632
Discover Financial Services	7,112		702,950
Futu Holdings Ltd., ADR (a)	13,171		682,916
LexinFintech Holdings Ltd., ADR (a)	164,476		445,730
Lufax Holding Ltd., ADR	76,244		155,538
Rocket Cos., Inc., Class A (a)	5,699		51,633
XP, Inc., Class A (a)	4,770		56,620
		$	2,372,019
Entertainment — 6.14%
CTS Eventim AG & Co. KGaA (a)	6,215		387,223
DraftKings, Inc., Class A (a)	3,258		63,075

See accompanying notes.

38

Schedule of Investments
Principal Millennial Global Growth ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Entertainment (continued)
HYBE Co. Ltd. (a)	2,332	$	338,376
Universal Music Group NV	21,240		536,825
Warner Music Group Corp., Class A	15,529		518,203
		$	1,843,702
Food — 2.75%
Albertsons Cos., Inc., Class A	3,974		82,580
Kroger Co.	13,661		674,444
Sprouts Farmers Market, Inc. (a)	1,984		69,499
		$	826,523
Home Builders — 0.84%
DR Horton, Inc.	1,766		172,521
Toll Brothers, Inc.	1,348		80,920
		$	253,441
Home Furnishings — 2.29%
Arhaus, Inc. (a)	7,447		61,736
Sleep Number Corp. (a)	1,250		38,012
Sony Group Corp.	5,500		496,460
Tempur Sealy International, Inc.	2,269		89,603
		$	685,811
Internet — 30.01%
AfreecaTV Co. Ltd.	4,876		317,613
Alphabet, Inc., Class C (a)	5,612		583,648
D-MARKET Elektronik Hizmetler ve Ticaret A/S, ADR (a)	30,559		40,949
eBay, Inc.	2,307		102,362
Expedia Group, Inc. (a)	2,647		256,838
Farfetch Ltd., Class A (a)	4,590		22,537
Hello Group, Inc., ADR	74,196		675,184
iQIYI, Inc., ADR (a)	94,876		690,697
JD.com, Inc., ADR	2,575		113,017
JOYY, Inc., ADR	17,514		546,087
Kakao Corp.	1,537		72,136
Kuaishou Technology (a),(b)	60,000		462,044
Lulu's Fashion Lounge Holdings, Inc. (a),(c)	9,349		22,251
Match Group, Inc. (a)	4,762		182,813
Meituan, Class B (a),(b)	280		5,119
Meta Platforms, Inc., Class A (a)	598		126,740
Naspers Ltd., Class N	5,021		928,613
Netflix, Inc. (a)	2,092		722,744
Pinterest, Inc., Class A (a)	5,346		145,785
RealReal, Inc. (a),(c)	8,731		11,001
Revolve Group, Inc. (a)	10,855		285,487
Rightmove PLC	8,326		57,825
Shutterstock, Inc.	683		49,586
Snap, Inc., Class A (a)	14,348		160,841
Temple & Webster Group Ltd. (a),(c)	13,808		31,751
Tencent Holdings Ltd.	3,000		147,441
Tencent Music Entertainment Group, ADR (a)	132,090		1,093,705
THG PLC (a),(c)	57,270		47,688
Trip.com Group Ltd., ADR (a)	24,732		931,654
Vipshop Holdings Ltd., ADR (a)	7,706		116,977
Weibo Corp., ADR (a)	2,829		56,750
		$	9,007,883

See accompanying notes.

39

	Schedule of Investments
	Principal Millennial Global Growth ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Leisure Time — 1.81%
Camping World Holdings, Inc., Class A	21,030	$	438,896
Shimano, Inc.	600		103,212
		$	542,108
Media — 4.21%
Comcast Corp., Class A	2,826		107,134
Fox Corp., Class B	3,618		113,279
Paramount Global, Class B	13,706		305,781
Sirius XM Holdings, Inc. (c)	20,006		79,424
Vivendi SE	65,108		656,669
		$	1,262,287
Real Estate — 0.44%
REA Group Ltd.	1,424		131,387
REITs — 3.02%
EastGroup Properties, Inc.	645		106,632
Equity Residential	1,458		87,480
Prologis, Inc.	817		101,937
Rexford Industrial Realty, Inc.	1,759		104,924
Segro PLC	48,415		458,447
Warehouses De Pauw CVA	1,594		47,228
		$	906,648
Retail — 16.71%
Academy Sports & Outdoors, Inc.	1,559		101,725
American Eagle Outfitters, Inc.	3,771		50,682
ANTA Sports Products Ltd.	11,400		165,556
Bath & Body Works, Inc.	2,743		100,339
Bed Bath & Beyond, Inc. (a)	17,140		7,326
Dick's Sporting Goods, Inc.	614		87,120
Foot Locker, Inc.	2,138		84,857
Frasers Group PLC (a)	8,311		79,662
Goldwin, Inc.	1,300		123,367
H & M Hennes & Mauritz AB, Class B	10,709		152,520
Hibbett, Inc.	1,388		81,864
Home Depot, Inc.	2,618		772,624
Industria de Diseno Textil SA	38,972		1,305,993
Kingfisher PLC	20,632		66,480
Li Ning Co. Ltd.	16,771		132,247
Lowe's Cos., Inc.	658		131,580
Lululemon Athletica, Inc. (a)	364		132,565
Next PLC	1,808		146,578
Pandora A/S	1,476		140,824
Petco Health & Wellness Co., Inc. (a)	3,237		29,133
Qurate Retail, Inc., Series A (a)	13,315		13,153
Ryohin Keikaku Co. Ltd.	5,740		65,019
Signet Jewelers Ltd.	8,848		688,197
Starbucks Corp.	1,445		150,468
Truworths International Ltd.	17,374		52,029
Victoria's Secret & Co. (a)	1,233		42,107
Williams-Sonoma, Inc.	907		110,346
		$	5,014,361
Semiconductors — 0.45%
NVIDIA Corp.	491		136,385

See accompanying notes.

40

		Schedule of Investments
	Principal Millennial Global Growth ETF
		March 31, 2023 (unaudited)
COMMON STOCKS (continued)			Shares Held		Value
Software — 5.25%
Bilibili, Inc., ADR (a)			16,631	$	390,829
DouYu International Holdings Ltd., ADR (a)			204,344		243,169
Fidelity National Information Services, Inc.			1,318		71,607
Fiserv, Inc. (a)			1,298		146,713
HUYA, Inc., ADR (a)			96,416		348,062
Kakao Games Corp. (a)			985		31,551
Microsoft Corp.			431		124,257
NetEase, Inc., ADR			1,620		143,273
XD, Inc. (a)			22,200		76,216
				$	1,575,677
Telecommunications — 2.82%
AT&T, Inc.			43,918		845,421
Toys, Games & Hobbies — 1.06%
Funko, Inc., Class A (a)			33,893		319,611
Transportation — 1.66%
Deutsche Post AG			2,985		139,492
FedEx Corp.			573		130,925
RXO, Inc. (a)			869		17,067
United Parcel Service, Inc., Class B			619		120,080
XPO, Inc. (a)			869		27,721
Yamato Holdings Co. Ltd.			3,700		63,230
				$	498,515
TOTAL COMMON STOCKS				$	29,774,747
INVESTMENT COMPANIES — 2.33%			Shares Held		Value
Money Market Funds — 2.33%
Principal Government Money Market Fund —Class R-6 4.72% (d),(e),(f)			572,569	$	572,569
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (f)			126,776		126,776
TOTAL INVESTMENT COMPANIES				$	699,345
Total Investments				$	30,474,092
Other Assets and Liabilities — (1.53)%					(460,103	)
Total Net Assets — 100.00%				$	30,013,989
(a)	Non-income producing security.
(b)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $1,036,900 or 3.45% of net assets.
(c)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $554,602 or
	1.85% of net assets.
(d)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(e)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $572,569 or 1.91% of net assets.
(f)	Current yield shown is as of period end.
See accompanying notes.		41

			Schedule of Investments
			Principal Millennial Global Growth ETF
			March 31, 2023 (unaudited)
Portfolio Summary
Location					Percent
United States						47.61	%
China						21.30	%
Spain						4.35	%
France						3.55	%
Netherlands						3.29	%
South Africa						3.27	%
United Kingdom						3.18	%
Japan						3.01	%
Republic Of Korea						2.76	%
Hong Kong						2.27	%
Germany						2.11	%
Singapore						1.82	%
Australia						0.77	%
Canada						0.77	%
Sweden						0.51	%
Denmark						0.47	%
Brazil						0.19	%
Belgium						0.16	%
Turkey						0.14	%
Other Assets and Liabilities						(1.53	)%
TOTAL NET ASSETS						100.00	%
			June 30, 2022		Purchases					Sales		March 31, 2023
Affiliated Securities			Value			Cost				Proceeds		Value
Principal Government Money
Market Fund — Class R-6 4.72%		$	—		$	4,758,029			$	4,185,460	$	572,569
Principal Government Money
Market Fund — Institutional Class
4.67	%		988,500			8,567,796				9,556,296		—
		$	988,500	$	13,325,825			$	13,741,756		$	572,569
									Realized Gain
						Realized				from		Change in
					Gain/(Loss) on				Capital Gain			Unrealized
			Income (a)		Investments				Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Class R-6 4.72%		$	—		$	—			$	—	$	—
Principal Government Money
Market Fund — Institutional Class
4.67	%		—			—				—		—
		$	—		$	—			$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

42

Schedule of Investments
Principal Quality ETF
March 31, 2023 (unaudited)
COMMON STOCKS — 99.78%	Shares Held		Value
Beverages — 1.18%
Keurig Dr Pepper, Inc.	9,716	$	342,780
Biotechnology — 1.52%
Amgen, Inc.	1,816		439,018
Commercial Services — 2.53%
Automatic Data Processing, Inc.	1,821		405,409
MarketAxess Holdings, Inc.	836		327,119
		$	732,528
Computers — 8.53%
Accenture PLC, Class A	1,787		510,742
Apple, Inc.	9,884		1,629,872
Leidos Holdings, Inc.	3,546		326,445
		$	2,467,059
Construction Materials — 1.25%
Trane Technologies PLC	1,960		360,601
Distribution/Wholesale — 3.51%
LKQ Corp.	5,957		338,119
Pool Corp.	951		325,661
WW Grainger, Inc.	510		351,293
		$	1,015,073
Diversified Financial Services — 2.02%
Mastercard, Inc., Class A	1,610		585,090
Electrical Components & Equipment — 2.57%
AMETEK, Inc.	2,494		362,453
Emerson Electric Co.	4,363		380,192
		$	742,645
Electronics — 3.68%
Agilent Technologies, Inc.	2,580		356,917
Keysight Technologies, Inc. (a)	2,172		350,735
Mettler-Toledo International, Inc. (a)	233		356,539
		$	1,064,191
Healthcare — Products — 10.11%
Abbott Laboratories	4,706		476,530
Danaher Corp.	1,845		465,014
Edwards Lifesciences Corp. (a)	4,407		364,591
Stryker Corp.	1,428		407,651
Thermo Fisher Scientific, Inc.	904		521,039
Waters Corp. (a)	1,099		340,283
West Pharmaceutical Services, Inc.	1,005		348,202
		$	2,923,310
Healthcare — Services — 6.02%
Charles River Laboratories International, Inc. (a)	1,669		336,838
Humana, Inc.	738		358,269
IQVIA Holdings, Inc. (a)	1,800		358,002
UnitedHealth Group, Inc.	1,457		688,564
		$	1,741,673
Home Builders — 2.34%
DR Horton, Inc.	3,483		340,254

See accompanying notes.

43

	Schedule of Investments
	Principal Quality ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
Home Builders (continued)
PulteGroup, Inc.		5,791	$	337,500
			$	677,754
Household Products/Wares — 1.21%
Avery Dennison Corp.		1,953		349,450
Insurance — 4.13%
Aon PLC, Class A		1,231		388,122
Arthur J Gallagher & Co.		1,922		367,698
Berkshire Hathaway, Inc., Class B (a)		107		33,038
Marsh & McLennan Cos., Inc.		2,431		404,883
			$	1,193,741
Internet — 4.30%
Alphabet, Inc., Class A (a)		941		97,610
Alphabet, Inc., Class C (a)		4,384		455,936
Amazon.com, Inc. (a)		3,306		341,477
CDW Corp.		1,782		347,294
			$	1,242,317
Machinery — Diversified — 2.42%
IDEX Corp.		1,504		347,469
Nordson Corp.		1,583		351,838
			$	699,307
Pharmaceuticals — 5.16%
AbbVie, Inc.		3,527		562,098
Merck & Co., Inc.		5,154		548,334
Zoetis, Inc.		2,301		382,978
			$	1,493,410
Pipelines — 1.25%
Williams Cos., Inc.		12,113		361,694
Retail — 4.96%
Genuine Parts Co.		2,033		340,141
O'Reilly Automotive, Inc. (a)		445		377,796
Ulta Beauty, Inc. (a)		662		361,233
Yum! Brands, Inc.		2,684		354,503
			$	1,433,673
Semiconductors — 14.41%
Analog Devices, Inc.		2,116		417,318
Applied Materials, Inc.		3,270		401,654
Broadcom, Inc.		850		545,309
Microchip Technology, Inc.		4,349		364,359
NVIDIA Corp.		3,297		915,808
NXP Semiconductors NV		1,988		370,712
ON Semiconductor Corp. (a)		4,372		359,903
QUALCOMM, Inc.		3,540		451,633
Skyworks Solutions, Inc.		2,884		340,254
			$	4,166,950
Software — 13.65%
Adobe, Inc. (a)		1,262		486,337
Fiserv, Inc. (a)		3,436		388,371
Intuit, Inc.		995		443,601
Microsoft Corp.		4,802		1,384,417

See accompanying notes.

44

			Schedule of Investments
			Principal Quality ETF
			March 31, 2023 (unaudited)
COMMON STOCKS (continued)								Shares Held		Value
Software (continued)
MSCI, Inc.								651	$	364,358
Salesforce, Inc. (a)								2,541		507,641
Synopsys, Inc. (a)								962		371,572
									$	3,946,297
Telecommunications — 1.76%
Cisco Systems, Inc.								9,719		508,061
Transportation — 1.27%
Norfolk Southern Corp.								1,731		366,972
TOTAL COMMON STOCKS									$	28,853,594
INVESTMENT COMPANIES — 0.18%								Shares Held		Value
Money Market Fund — 0.18%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (b)								52,798	$	52,798
TOTAL INVESTMENT COMPANIES									$	52,798
Total Investments									$	28,906,392
Other Assets and Liabilities — 0.04%										12,479
Total Net Assets — 100.00%									$	28,918,871
(a)	Non-income producing security.
(b)	Current yield shown is as of period end.
	Portfolio Summary
Sector				Percent
Technology					36.60	%
Consumer, Non-cyclical					27.74	%
Industrial					11.18	%
Consumer, Cyclical					10.81	%
Financial					6.15	%
Communications					6.05	%
Energy					1.25	%
Money Market Fund					0.18	%
Other Assets and Liabilities					0.04	%
TOTAL NET ASSETS					100.00	%
		June 30, 2022		Purchases				Sales		March 31, 2023
Affiliated Securities			Value		Cost			Proceeds		Value
Principal Government Money
Market Fund — Class R-6 4.72%		$	—	$	59,105		$	59,105	$	—
		$	—	$	59,105		$	59,105	$	—
								Realized Gain
					Realized			from		Change in
				Gain/(Loss) on				Capital Gain		Unrealized
			Income (a)	Investments				Distributions		Gain/(Loss)
Principal Government Money
Market Fund — Class R-6 4.72%		$	—	$	—		$	—	$	—
		$	—	$	—		$	—	$	—
(a)	Amount excludes earnings from securities lending collateral.
See accompanying notes.				45

	Schedule of Investments
Principal Real Estate Active Opportunities ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 98.63%	Shares Held			Value
Entertainment — 2.21%
Marriott Vacations Worldwide Corp.	832		$	112,204
REITs — 96.42%
Alexandria Real Estate Equities, Inc.	1,628			204,460
American Homes 4 Rent, Class A	6,946			218,452
American Tower Corp.	1,840			375,986
Crown Castle, Inc.	1,648			220,568
CubeSmart	4,509			208,406
DiamondRock Hospitality Co.	12,332			100,259
Digital Realty Trust, Inc.	2,269			223,065
Equinix, Inc.	199			143,487
Equity LifeStyle Properties, Inc.	3,387			227,369
Extra Space Storage, Inc.	2,098			341,827
Gaming & Leisure Properties, Inc.	3,319			172,787
Invitation Homes, Inc.	10,368			323,793
Medical Properties Trust, Inc.	4,213			34,631
National Health Investors, Inc.	1,952			100,684
Rexford Industrial Realty, Inc.	6,586			392,855
SBA Communications Corp.	783			204,418
Sun Communities, Inc.	2,276			320,643
Terreno Realty Corp.	2,946			190,312
Ventas, Inc.	7,171			310,863
VICI Properties, Inc.	10,006			326,396
Welltower, Inc.	3,411			244,534
			$	4,885,795
TOTAL COMMON STOCKS			$	4,997,999
INVESTMENT COMPANIES — 0.99%	Shares Held			Value
Money Market Fund — 0.99%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (a)	49,923		$	49,923
TOTAL INVESTMENT COMPANIES			$	49,923
Total Investments			$	5,047,922
Other Assets and Liabilities — 0.38%				19,279
Total Net Assets — 100.00%			$	5,067,201
(a) Current yield shown is as of period end.
Portfolio Summary
Sector	Percent
Financial	96.42	%
Consumer, Cyclical	2.21	%
Money Market Fund	0.99	%
Other Assets and Liabilities	0.38	%
TOTAL NET ASSETS	100.00	%
See accompanying notes.	46

Schedule of Investments
Principal Spectrum Preferred Securities Active ETF
March 31, 2023 (unaudited)
		Principal
BONDS — 95.03%		Amount		Value
Banks — 46.85%
Bank of America Corp.
(5-year Treasury Constant Maturity Rate + 2.76%),
4.38%, 01/27/2027 (a),(b)	$	10,268,000	$	8,729,215
(5-year Treasury Constant Maturity Rate + 3.23%),
6.13%, 04/27/2027 (a),(b),(c)		10,776,000		10,600,890
Bank of Montreal
(5-year Treasury Constant Maturity Rate + 2.98%),
4.80%, 08/25/2024 (a),(b)		3,362,000		2,892,433
Bank of New York Mellon Corp.
(5-year Treasury Constant Maturity Rate + 3.35%),
3.70%, 03/20/2026 (a),(b)		11,569,000		10,441,023
(5-year Treasury Constant Maturity Rate + 2.63%),
3.75%, 12/20/2026 (a),(b)		3,447,000		2,842,396
Bank of Nova Scotia
(5-year Treasury Constant Maturity Rate + 4.55%),
4.90%, 06/04/2025 (a),(b)		4,565,000		4,154,150
(5-year Treasury Constant Maturity Rate + 4.38%),
8.63%, 10/27/2082 (a)		12,585,000		12,819,726
Citigroup, Inc.
(5-year Treasury Constant Maturity Rate + 3.42%),
3.88%, 02/18/2026 (a),(b)		7,702,000		6,504,339
(5-year Treasury Constant Maturity Rate + 3.60%),
4.00%, 12/10/2025 (a),(b)		13,081,000		11,560,334
(5-year Treasury Constant Maturity Rate + 3.20%),
7.38%, 05/15/2028 (a),(b)		6,600,000		6,495,456
Citizens Financial Group, Inc.
(5-year Treasury Constant Maturity Rate + 3.22%),
4.00%, 10/06/2026 (a),(b)		3,206,000		2,444,575
(5-year Treasury Constant Maturity Rate + 5.31%),
5.65%, 10/06/2025 (a),(b)		4,583,000		3,954,817
Comerica, Inc.
(5-year Treasury Constant Maturity Rate + 5.29%),
5.63%, 07/01/2025 (a),(b)		13,611,000		11,410,101
Goldman Sachs Group, Inc.
(5-year Treasury Constant Maturity Rate + 2.92%),
3.65%, 08/10/2026 (a),(b)		1,910,000		1,559,038
(5-year Treasury Constant Maturity Rate + 2.97%),
3.80%, 05/10/2026 (a),(b)		1,284,000		1,063,537
(5-year Treasury Constant Maturity Rate + 2.95%),
4.13%, 11/10/2026 (a),(b)		8,542,000		7,079,236
(5-year Treasury Constant Maturity Rate + 3.62%),
5.50%, 08/10/2024 (a),(b)		8,268,000		7,976,718
HSBC Capital Funding Dollar 1 LP
(3-month USD LIBOR + 4.98%),
10.18%, 06/30/2030 (a),(b)		5,868,000		7,035,209
Huntington Bancshares, Inc.
(10-year Treasury Constant Maturity Rate + 4.95%),
5.63%, 07/15/2030 (a),(b)		6,707,000		5,700,950
JPMorgan Chase & Co.
(5-year Treasury Constant Maturity Rate + 2.85%),
3.65%, 06/01/2026 (a),(b)		9,269,000		8,110,375
(3-month USD LIBOR + 3.78%),
6.75%, 02/01/2024 (a),(b)		7,688,000		7,714,754
M&T Bank Corp.
(5-year Treasury Constant Maturity Rate + 2.68%),
3.50%, 09/01/2026 (a),(b)		19,512,000		13,736,328

See accompanying notes.

47

Schedule of Investments
Principal Spectrum Preferred Securities Active ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
M&T Bank Corp. (continued)
(5-year Treasury Constant Maturity Rate + 3.17%),
5.00%, 08/01/2024 (a),(b)	$	5,000,000	$	3,950,000
PNC Financial Services Group, Inc.
(5-year Treasury Constant Maturity Rate + 2.60%),
3.40%, 09/15/2026 (a),(b)		2,820,000		2,236,316
(5-year Treasury Constant Maturity Rate + 3.24%),
6.20%, 09/15/2027 (a),(b),(c)		13,480,000		12,682,658
Toronto-Dominion Bank
(5-year Treasury Constant Maturity Rate + 4.07%),
8.13%, 10/31/2082 (a)		22,075,000		22,406,125
Truist Financial Corp.
(5-year Treasury Constant Maturity Rate + 3.00%),
4.80%, 09/01/2024 (a),(b)		6,129,000		5,362,875
(5-year Treasury Constant Maturity Rate + 4.61%),
4.95%, 09/01/2025 (a),(b)		10,237,000		9,461,871
U.S. Bancorp
(5-year Treasury Constant Maturity Rate + 2.54%),
3.70%, 01/15/2027 (a),(b)		12,377,000		9,654,060
Wells Fargo & Co.
(5-year Treasury Constant Maturity Rate + 3.45%),
3.90%, 03/15/2026 (a),(b)		23,171,000		20,453,273
			$	241,032,778
Diversified Financial Services — 8.33%
American Express Co.
(5-year Treasury Constant Maturity Rate + 2.85%),
3.55%, 09/15/2026 (a),(b)		12,422,000		10,499,074
Capital One Financial Corp.
(5-year Treasury Constant Maturity Rate + 3.16%),
3.95%, 09/01/2026 (a),(b)		13,521,000		10,123,849
Charles Schwab Corp.
(5-year Treasury Constant Maturity Rate + 3.17%),
4.00%, 06/01/2026 (a),(b)		12,862,000		10,486,003
(5-year Treasury Constant Maturity Rate + 4.97%),
5.38%, 06/01/2025 (a),(b)		2,494,000		2,363,065
Discover Financial Services
(5-year Treasury Constant Maturity Rate + 5.78%),
6.13%, 06/23/2025 (a),(b)		10,141,000		9,360,485
			$	42,832,476
Electric — 12.07%
Algonquin Power & Utilities Corp.
(5-year Treasury Constant Maturity Rate + 3.25%),
4.75%, 01/18/2082 (a)		3,010,000		2,408,000
American Electric Power Co., Inc.
(5-year Treasury Constant Maturity Rate + 2.68%),
3.88%, 02/15/2062 (a)		8,947,000		7,127,726
CMS Energy Corp.
(5-year Treasury Constant Maturity Rate + 4.12%),
4.75%, 06/01/2050 (a)		2,476,000		2,139,214
Dominion Energy, Inc.
(5-year Treasury Constant Maturity Rate + 3.20%),
4.35%, 01/15/2027 (a),(b)		712,000		589,003
(5-year Treasury Constant Maturity Rate + 2.99%),
4.65%, 12/15/2024 (a),(b),(c)		11,434,000		10,045,226

See accompanying notes.

48

Schedule of Investments
Principal Spectrum Preferred Securities Active ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Electric (continued)
Duke Energy Corp.
(5-year Treasury Constant Maturity Rate + 2.32%),
3.25%, 01/15/2082 (a)	$	4,456,000	$	3,318,606
(5-year Treasury Constant Maturity Rate + 3.39%),
4.88%, 09/16/2024 (a),(b),(c)		13,948,000		13,384,501
Emera, Inc.
(3-month USD LIBOR + 5.44%),
6.75%, 06/15/2076 (a)		6,187,000		5,764,950
Enel SpA
(5-year Swap rate + 5.88%),
8.75%, 09/24/2073 (a),(d)		3,335,000		3,308,417
NextEra Energy Capital Holdings, Inc.
(5-year Treasury Constant Maturity Rate + 2.55%),
3.80%, 03/15/2082 (a)		14,529,000		11,986,425
Southern Co.
(5-year Treasury Constant Maturity Rate + 3.73%),
4.00%, 01/15/2051 (a)		2,231,000		2,046,803
			$	62,118,871
Gas — 1.03%
NiSource, Inc.
(5-year Treasury Constant Maturity Rate + 2.84%),
5.65%, 06/15/2023 (a),(b)		5,628,000		5,290,320
Hand/Machine Tools — 0.58%
Stanley Black & Decker, Inc.
(5-year Treasury Constant Maturity Rate + 2.66%),
4.00%, 03/15/2060 (a)		3,816,000		3,006,717
Insurance — 16.60%
Allstate Corp.
(3-month USD LIBOR + 2.94%),
5.75%, 08/15/2053 (a)		3,210,000		3,125,828
American International Group, Inc.
(3-month USD LIBOR + 2.87%),
5.75%, 04/01/2048 (a)		1,192,000		1,093,422
Argentum Netherlands BV for Swiss Re Ltd.
(3-month USD LIBOR + 3.78%),
5.63%, 08/15/2052 (a)		5,600,000		5,208,000
Argentum Netherlands BV for Zurich Insurance Co. Ltd.
(5-year Treasury Constant Maturity Rate + 3.27%),
5.13%, 06/01/2048 (a)		4,000,000		3,735,000
Cloverie PLC for Zurich Insurance Co. Ltd.
(3-month USD LIBOR + 4.92%),
5.63%, 06/24/2046 (a)		5,600,000		5,419,456
Corebridge Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.85%),
6.88%, 12/15/2052 (a),(c),(d)		7,521,000		6,704,599
Equitable Holdings, Inc.
(5-year Treasury Constant Maturity Rate + 4.74%),
4.95%, 09/15/2025 (a),(b),(c)		3,555,000		3,240,146
Liberty Mutual Group, Inc.
(5-year Treasury Constant Maturity Rate + 3.32%),
4.13%, 12/15/2051 (a),(d)		2,612,000		2,094,615
Meiji Yasuda Life Insurance Co.
(5-year Swap rate + 4.23%),
5.20%, 10/20/2045 (a),(d)		3,210,000		3,100,712

See accompanying notes.

49

Schedule of Investments
Principal Spectrum Preferred Securities Active ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Insurance (continued)
MetLife, Inc.
(5-year Treasury Constant Maturity Rate + 3.58%),
3.85%, 09/15/2025 (a),(b)	$	8,593,000	$	7,570,891
9.25%, 04/08/2068 (d)		1,415,000		1,669,626
Nippon Life Insurance Co.
(5-year Treasury Constant Maturity Rate + 2.65%),
2.75%, 01/21/2051 (a),(d)		4,238,000		3,361,384
(5-year Treasury Constant Maturity Rate + 2.60%),
2.90%, 09/16/2051 (a),(d)		2,505,000		1,996,925
Prudential Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.04%),
3.70%, 10/01/2050 (a)		14,098,000		11,483,794
(5-year Treasury Constant Maturity Rate + 3.16%),
5.13%, 03/01/2052 (a)		4,634,000		4,082,976
Sumitomo Life Insurance Co.
(5-year Treasury Constant Maturity Rate + 2.75%),
3.38%, 04/15/2081 (a),(d)		3,860,000		3,232,750
(3-month USD LIBOR + 4.44%),
6.50%, 09/20/2073 (a),(d)		6,436,000		6,379,896
Voya Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.36%),
6.13%, 09/15/2023 (a),(b)		7,690,000		7,331,132
Zurich Finance Ireland Designated Activity Co.
(5-year Treasury Constant Maturity Rate + 2.78%),
3.00%, 04/19/2051 (a)		6,000,000		4,546,320
			$	85,377,472
Oil & Gas — 1.38%
BP Capital Markets PLC
(5-year Treasury Constant Maturity Rate + 4.04%),
4.38%, 06/22/2025 (a),(b)		5,000,000		4,762,068
(5-year Treasury Constant Maturity Rate + 4.40%),
4.88%, 03/22/2030 (a),(b)		2,561,000		2,327,309
			$	7,089,377
Pipelines — 5.80%
Enbridge, Inc.
(5-year Treasury Constant Maturity Rate + 5.31%),
5.75%, 07/15/2080 (a)		1,845,000		1,641,483
(3-month USD LIBOR + 3.89%),
6.00%, 01/15/2077 (a)		4,782,000		4,414,719
(5-year Treasury Constant Maturity Rate + 4.41%),
7.63%, 01/15/2083 (a)		5,245,000		5,116,430
Enterprise Products Operating LLC
(3-month USD LIBOR + 3.03%),
5.25%, 08/16/2077 (a)		3,210,000		2,714,441
Transcanada Trust
(6-month Secured Overnight Financing Rate + 4.42%),
5.50%, 09/15/2079 (a)		5,115,000		4,266,841
(5-year Treasury Constant Maturity Rate + 3.99%),
5.60%, 03/07/2082 (a)		13,953,000		11,671,530
			$	29,825,444
REITs — 0.58%
Scentre Group Trust 2
(5-year Treasury Constant Maturity Rate + 4.38%),
4.75%, 09/24/2080 (a),(d)		1,210,000		1,089,334

See accompanying notes.

50

	Schedule of Investments
	Principal Spectrum Preferred Securities Active ETF
	March 31, 2023 (unaudited)
			Principal
BONDS (continued)			Amount		Value
REITs (continued)
Scentre Group Trust 2 (continued)
	(5-year Treasury Constant Maturity Rate + 4.69%),
	5.13%, 09/24/2080 (a),(d)	$	2,249,000	$	1,898,252
				$	2,987,586
Telecommunications — 1.81%
Vodafone Group PLC
	(5-year Treasury Constant Maturity Rate + 2.77%),
	4.13%, 06/04/2081 (a)		1,793,000		1,414,982
	(5-year Swap rate + 4.87%),
	7.00%, 04/04/2079 (a)		7,931,000		7,895,072
				$	9,310,054
TOTAL BONDS				$	488,871,095
INVESTMENT COMPANIES — 6.56%			Shares Held		Value
Money Market Funds — 6.56%
Principal Government Money Market Fund — Class R-6 4.72% (e),(f),(g)			19,419,230	$	19,419,230
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (g)			14,319,518		14,319,518
TOTAL INVESTMENT COMPANIES				$	33,738,748
Total Investments				$	522,609,843
Other Assets and Liabilities — (1.59)%					(8,187,017	)
Total Net Assets — 100.00%				$	514,422,826
(a)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or
	floating rate in the future.
(b)	Perpetual security. Perpetual securities pay an indefinite stream of interest, but they may be called by the issuer at an earlier
	date. Date shown, if any, reflects the next call date or final legal maturity date. Rate shown is as of period end.
(c)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $19,088,640 or
	3.71% of net assets.
(d)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in
	transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these
	securities totaled $34,836,510 or 6.77% of net assets.
(e)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(f)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $19,419,230 or 3.77% of net assets.
(g)	Current yield shown is as of period end.
See accompanying notes.		51

			Schedule of Investments
		Principal Spectrum Preferred Securities Active ETF
			March 31, 2023 (unaudited)
Portfolio Summary
Sector					Percent
Financial						72.36	%
Utilities						13.10	%
Energy						7.18	%
Money Market Funds						6.56	%
Communications						1.81	%
Industrial						0.58	%
Other Assets and Liabilities						(1.59	)%
TOTAL NET ASSETS						100.00	%
			June 30, 2022		Purchases					Sales		March 31, 2023
Affiliated Securities			Value			Cost				Proceeds		Value
Principal Government Money
Market Fund — Class R-6 4.72%		$	—	$	51,062,488			$	31,643,258		$	19,419,230
Principal Government Money
Market Fund — Institutional Class
4.67	%		2,707,203			11,373,540				14,080,743		—
		$	2,707,203	$	62,436,028			$	45,724,001		$	19,419,230
									Realized Gain
						Realized				from		Change in
					Gain/(Loss) on				Capital Gain			Unrealized
			Income (a)		Investments				Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Class R-6 4.72%		$	—		$	—			$	—	$	—
Principal Government Money
Market Fund — Institutional Class
4.67	%		—			—				—		—
		$	—		$	—			$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

52

Schedule of Investments
Principal Spectrum Tax-Advantaged Dividend Active ETF
March 31, 2023 (unaudited)
PREFERRED STOCKS — 12.27%		Shares Held		Value
Banks — 5.23%
Associated Banc-Corp.; Series F
5.63%, 09/15/2025 (a)		2,070	$	40,282
Bank of America Corp.; Series NN
4.38%, 11/03/2025 (a)		4,380		81,337
Fulton Financial Corp.; Series A
5.13%, 01/15/2026 (a)		9,200		152,996
Morgan Stanley; Series I
(3-month USD LIBOR + 3.71%),
6.38%, 10/15/2024 (a)		17,030		419,449
Morgan Stanley; Series P
6.50%, 10/15/2027 (a)		4,000		101,560
Synovus Financial Corp.; Series E
(5-year Treasury Constant Maturity Rate + 4.13%),
5.88%, 07/01/2024 (a)		11,500		249,550
			$	1,045,174
Insurance — 4.11%
Allstate Corp.; Series H
5.10%, 10/15/2024 (a)		11,500		258,405
American International Group, Inc.; Series A
5.85%, 03/15/2024 (a)		8,019		187,324
MetLife, Inc.; Series F
4.75%, 03/15/2025 (a)		17,250		375,532
			$	821,261
Telecommunications — 2.93%
AT&T, Inc.; Series A
5.00%, 12/12/2024 (a)		11,381		257,893
AT&T, Inc.; Series C
4.75%, 02/18/2025 (a)		15,395		327,452
			$	585,345
TOTAL PREFERRED STOCKS			$	2,451,780
		Principal
BONDS — 84.78%		Amount		Value
Banks — 70.27%
Bank of America Corp.
(3-month USD LIBOR + 4.55%),
6.30%, 03/10/2026 (a),(b)	$	575,000	$	574,281
Bank of New York Mellon Corp.
(5-year Treasury Constant Maturity Rate + 3.35%),
3.70%, 03/20/2026 (a),(b)		230,000		207,575
(5-year Treasury Constant Maturity Rate + 4.36%),
4.70%, 09/20/2025 (a),(b)		275,000		260,224
Bank of Nova Scotia
(5-year Treasury Constant Maturity Rate + 4.55%),
4.90%, 06/04/2025 (a),(b)		575,000		523,250
(5-year Treasury Constant Maturity Rate + 4.38%),
8.63%, 10/27/2082 (b)		300,000		305,595
BNP Paribas SA
(5-year Treasury Constant Maturity Rate + 4.90%),
7.75%, 08/16/2029 (a),(b),(c),(d)		200,000		191,440
Citigroup, Inc.
(5-year Treasury Constant Maturity Rate + 3.42%),
3.88%, 02/18/2026 (a),(b)		655,000		553,147
(5-year Treasury Constant Maturity Rate + 3.20%),
7.38%, 05/15/2028 (a),(b)		200,000		196,832
See accompanying notes.	53

Schedule of Investments
Principal Spectrum Tax-Advantaged Dividend Active ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
Citizens Financial Group, Inc.
(5-year Treasury Constant Maturity Rate + 5.31%),
5.65%, 10/06/2025 (a),(b)	$	575,000	$	496,186
Comerica, Inc.
(5-year Treasury Constant Maturity Rate + 5.29%),
5.63%, 07/01/2025 (a),(b)		575,000		482,022
Credit Agricole SA
(5-year Swap Rate + 4.90%),
7.88%, 01/23/2024 (a),(b),(d)		861,000		841,214
Fifth Third Bancorp
(5-year Treasury Constant Maturity Rate + 4.22%),
4.50%, 09/30/2025 (a),(b)		548,000		475,191
Goldman Sachs Group, Inc.
(5-year Treasury Constant Maturity Rate + 2.97%),
3.80%, 05/10/2026 (a),(b)		438,000		362,795
HSBC Holdings PLC
(6-month U.S. International Swaps and Derivative Association + 4.37%),
6.38%, 03/30/2025 (a),(b),(d)		861,000		791,219
Huntington Bancshares, Inc.
(10-year Treasury Constant Maturity Rate + 4.95%),
5.63%, 07/15/2030 (a),(b)		575,000		488,750
ING Groep NV
(5-year Treasury Constant Maturity Rate + 4.34%),
5.75%, 11/16/2026 (a),(b),(d)		861,000		744,903
JPMorgan Chase & Co.
(5-year Treasury Constant Maturity Rate + 2.85%),
3.65%, 06/01/2026 (a),(b)		110,000		96,250
Lloyds Banking Group PLC
(5-year Swap Rate + 4.50%),
7.50%, 09/27/2025 (a),(b),(d)		861,000		798,853
M&T Bank Corp.
(3-month USD LIBOR + 3.52%),
5.13%, 11/01/2026 (a),(b)		247,000		185,151
Natwest Group PLC
(5-year Swap Rate + 5.72%),
8.00%, 08/10/2025 (a),(b),(d)		861,000		851,185
Nordea Bank Abp
(5-year Treasury Constant Maturity Rate + 4.11%),
6.63%, 03/26/2026 (a),(b),(c),(d)		861,000		806,938
PNC Financial Services Group, Inc.
(5-year Treasury Constant Maturity Rate + 3.00%),
6.00%, 05/15/2027 (a),(b)		400,000		368,224
(5-year Treasury Constant Maturity Rate + 3.24%),
6.20%, 09/15/2027 (a),(b)		100,000		94,085
Societe Generale SA
(5-year Swap rate + 4.98%),
7.88%, 12/18/2023 (a),(b),(d)		824,000		771,594
Toronto-Dominion Bank
(5-year Treasury Constant Maturity Rate + 4.07%),
8.13%, 10/31/2082 (b)		414,000		420,210
Truist Financial Corp.
(5-year Treasury Constant Maturity Rate + 4.61%),
4.95%, 09/01/2025 (a),(b)		575,000		531,462
U.S. Bancorp
(5-year Treasury Constant Maturity Rate + 2.54%),
3.70%, 01/15/2027 (a),(b)		209,000		163,020

See accompanying notes.

54

Schedule of Investments
Principal Spectrum Tax-Advantaged Dividend Active ETF
March 31, 2023 (unaudited)
		Principal
BONDS (continued)		Amount		Value
Banks (continued)
UBS Group AG
(5-year Swap rate + 4.34%),
7.00%, 01/31/2024 (a),(b),(d)	$	861,000	$	816,839
Wells Fargo & Co.
(5-year Treasury Constant Maturity Rate + 3.45%),
3.90%, 03/15/2026 (a),(b)		328,000		289,529
(3-month USD LIBOR + 3.99%),
5.88%, 06/15/2025 (a),(b)		355,000		348,788
			$	14,036,752
Diversified Financial Services — 6.56%
Capital One Financial Corp.
(5-year Treasury Constant Maturity Rate + 3.16%),
3.95%, 09/01/2026 (a),(b)		209,000		156,489
Charles Schwab Corp.
(5-year Treasury Constant Maturity Rate + 3.17%),
4.00%, 06/01/2026 (a),(b)		328,000		267,409
(5-year Treasury Constant Maturity Rate + 4.97%),
5.38%, 06/01/2025 (a),(b)		375,000		355,312
Discover Financial Services
(5-year Treasury Constant Maturity Rate + 5.78%),
6.13%, 06/23/2025 (a),(b)		575,000		530,744
			$	1,309,954
Electric — 4.78%
Dominion Energy, Inc.
(5-year Treasury Constant Maturity Rate + 2.99%),
4.65%, 12/15/2024 (a),(b)		460,000		404,129
Duke Energy Corp.
(5-year Treasury Constant Maturity Rate + 3.39%),
4.88%, 09/16/2024 (a),(b)		575,000		551,770
			$	955,899
Insurance — 3.17%
MetLife, Inc.
(5-year Treasury Constant Maturity Rate + 3.58%),
3.85%, 09/15/2025 (a),(b)		220,000		193,832
Voya Financial, Inc.
(5-year Treasury Constant Maturity Rate + 3.36%),
6.13%, 09/15/2023 (a),(b)		460,000		438,533
			$	632,365
TOTAL BONDS			$	16,934,970
INVESTMENT COMPANIES — 2.07%		Shares Held		Value
Money Market Fund — 2.07%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (e)		413,785	$	413,785
TOTAL INVESTMENT COMPANIES			$	413,785
Total Investments			$	19,800,535
Other Assets and Liabilities — 0.88%				175,049
Total Net Assets — 100.00%			$	19,975,584
(a) Perpetual security. Perpetual securities pay an indefinite stream of interest, but they may be called by the issuer at an earlier
date. Date shown, if any, reflects the next call date or final legal maturity date. Rate shown is as of period end.
See accompanying notes.	55

Schedule of Investments

Principal Spectrum Tax-Advantaged Dividend Active ETF

March 31, 2023 (unaudited)

(b)	Rate shown is as of period end. The rate may be a variable or floating rate or a fixed rate which may convert to a variable or floating rate in the future.
(c)	Security exempt from registration under Rule 144A of the Securities Act of 1933. These securities may be resold in transactions exempt from registration, normally to qualified institutional buyers. At the end of the period, the value of these securities totaled $998,378 or 5.00% of net assets.
(d)	Security is a contingent convertible security, ("CoCo"). CoCo's are hybrid debt securities that may convert to equity or have their principal written down upon occurrence of certain "triggers". At the end of the period, the value of these securities totaled $6,614,185 or 33.11% of net assets.
(e)	Current yield shown is as of period end.

Portfolio Summary
Sector	Percent
Financial	89.34	%
Utilities	4.78	%
Communications	2.93	%
Money Market Fund	2.07	%
Other Assets and Liabilities	0.88	%
TOTAL NET ASSETS	100.00	%

See accompanying notes.

56

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 99.25%	Shares Held		Value
Advertising — 0.41%
Interpublic Group of Cos., Inc.	326	$	12,140
Omnicom Group, Inc.	138		13,019
		$	25,159
Aerospace & Defense — 1.61%
Boeing Co. (a)	43		9,135
General Dynamics Corp.	57		13,008
Howmet Aerospace, Inc.	111		4,703
L3Harris Technologies, Inc.	8		1,570
Lockheed Martin Corp.	59		27,891
Northrop Grumman Corp.	45		20,777
Raytheon Technologies Corp.	140		13,710
TransDigm Group, Inc.	9		6,633
		$	97,427
Agriculture — 0.66%
Altria Group, Inc.	206		9,192
Archer-Daniels-Midland Co.	151		12,028
Bunge Ltd.	42		4,012
Philip Morris International, Inc.	151		14,685
		$	39,917
Airlines — 0.34%
American Airlines Group, Inc. (a)	232		3,422
Delta Air Lines, Inc. (a)	258		9,009
United Airlines Holdings, Inc. (a)	182		8,054
		$	20,485
Apparel — 0.42%
NIKE, Inc., Class B	91		11,160
Ralph Lauren Corp.	57		6,650
Tapestry, Inc.	176		7,588
		$	25,398
Auto Manufacturers — 2.24%
Cummins, Inc.	65		15,527
General Motors Co.	171		6,273
PACCAR, Inc.	221		16,177
Tesla, Inc. (a)	472		97,921
		$	135,898
Auto Parts & Equipment — 0.26%
Aptiv PLC (a)	38		4,263
BorgWarner, Inc.	232		11,394
		$	15,657
Banks — 3.77%
Bank of America Corp.	489		13,985
Bank of New York Mellon Corp.	218		9,906
Citigroup, Inc.	172		8,065
Citizens Financial Group, Inc.	131		3,979
Comerica, Inc.	88		3,821
Fifth Third Bancorp	165		4,396
First Republic Bank (a)	470		6,575
Goldman Sachs Group, Inc.	63		20,608
Huntington Bancshares, Inc.	997		11,166
JPMorgan Chase & Co.	514		66,979

See accompanying notes.

57

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Banks (continued)
KeyCorp	329	$	4,119
M&T Bank Corp.	38		4,544
Morgan Stanley	231		20,282
Northern Trust Corp.	51		4,495
PNC Financial Services Group, Inc.	48		6,101
Regions Financial Corp.	236		4,380
State Street Corp.	120		9,083
Truist Financial Corp.	172		5,865
U.S. Bancorp	169		6,092
Wells Fargo & Co.	292		10,915
Zions Bancorp NA	126		3,771
		$	229,127
Beverages — 1.69%
Brown-Forman Corp., Class B	62		3,985
Coca-Cola Co.	573		35,543
Constellation Brands, Inc., Class A	26		5,873
Keurig Dr Pepper, Inc.	38		1,340
Molson Coors Beverage Co., Class B	157		8,114
Monster Beverage Corp. (a)	204		11,018
PepsiCo, Inc.	203		37,007
		$	102,880
Biotechnology — 1.53%
Amgen, Inc.	91		21,999
Biogen, Inc. (a)	37		10,287
Corteva, Inc.	114		6,875
Gilead Sciences, Inc.	240		19,913
Incyte Corp. (a)	64		4,625
Moderna, Inc. (a)	39		5,990
Regeneron Pharmaceuticals, Inc. (a)	9		7,395
Vertex Pharmaceuticals, Inc. (a)	50		15,754
		$	92,838
Chemicals — 1.89%
Air Products & Chemicals, Inc.	49		14,073
Albemarle Corp.	56		12,378
Celanese Corp.	38		4,138
CF Industries Holdings, Inc.	102		7,394
Dow, Inc.	130		7,127
DuPont de Nemours, Inc.	84		6,029
Eastman Chemical Co.	48		4,048
FMC Corp.	63		7,694
Linde PLC	77		27,369
LyondellBasell Industries NV, Class A	109		10,234
Mosaic Co.	97		4,450
PPG Industries, Inc.	33		4,408
Sherwin-Williams Co.	24		5,395
		$	114,737
Commercial Services — 1.96%
Automatic Data Processing, Inc.	79		17,588
Cintas Corp.	24		11,104
CoStar Group, Inc. (a)	116		7,987
FleetCor Technologies, Inc. (a)	36		7,591
Gartner, Inc. (a)	28		9,121
MarketAxess Holdings, Inc.	17		6,652
PayPal Holdings, Inc. (a)	88		6,683

See accompanying notes.

58

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Commercial Services (continued)
Quanta Services, Inc.	51	$	8,499
Robert Half International, Inc.	86		6,929
Rollins, Inc.	180		6,755
S&P Global, Inc.	33		11,377
United Rentals, Inc.	33		13,060
Verisk Analytics, Inc.	29		5,564
		$	118,910
Computers — 8.57%
Accenture PLC, Class A	86		24,580
Apple, Inc.	2,610		430,389
Cognizant Technology Solutions Corp., Class A	150		9,139
DXC Technology Co. (a)	153		3,911
EPAM Systems, Inc. (a)	24		7,176
Fortinet, Inc. (a)	71		4,719
Hewlett Packard Enterprise Co.	379		6,037
HP, Inc.	166		4,872
International Business Machines Corp.	92		12,060
Leidos Holdings, Inc.	87		8,009
NetApp, Inc.	81		5,172
Seagate Technology Holdings PLC	63		4,166
		$	520,230
Construction Materials — 0.74%
Carrier Global Corp.	319		14,594
Johnson Controls International PLC	82		4,938
Martin Marietta Materials, Inc.	10		3,551
Masco Corp.	148		7,359
Trane Technologies PLC	50		9,199
Vulcan Materials Co.	31		5,318
		$	44,959
Distribution/Wholesale — 0.80%
Copart, Inc. (a)	133		10,003
Fastenal Co.	99		5,340
LKQ Corp.	215		12,204
Pool Corp.	21		7,191
WW Grainger, Inc.	20		13,776
		$	48,514
Diversified Financial Services — 3.64%
American Express Co.	96		15,835
Ameriprise Financial, Inc.	32		9,808
BlackRock, Inc.	24		16,059
Capital One Financial Corp.	53		5,097
Cboe Global Markets, Inc.	35		4,698
Charles Schwab Corp.	122		6,390
CME Group, Inc.	43		8,235
Discover Financial Services	48		4,744
Franklin Resources, Inc.	261		7,031
Intercontinental Exchange, Inc.	71		7,405
Invesco Ltd.	245		4,018
Mastercard, Inc., Class A	127		46,153
Nasdaq, Inc.	161		8,802
Raymond James Financial, Inc.	84		7,835
Synchrony Financial	261		7,590
T Rowe Price Group, Inc.	43		4,855

See accompanying notes.

59

Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Diversified Financial Services (continued)
Visa, Inc., Class A	251	$	56,590
		$	221,145
Electric — 1.93%
AES Corp.	154		3,708
Alliant Energy Corp.	77		4,112
Ameren Corp.	55		4,751
American Electric Power Co., Inc.	75		6,824
CenterPoint Energy, Inc.	39		1,149
CMS Energy Corp.	72		4,419
Consolidated Edison, Inc.	103		9,854
Constellation Energy Corp.	53		4,161
Dominion Energy, Inc.	30		1,677
DTE Energy Co.	44		4,820
Duke Energy Corp.	87		8,393
Edison International	79		5,577
Entergy Corp.	12		1,293
Evergy, Inc.	18		1,100
Eversource Energy	65		5,087
Exelon Corp.	38		1,592
FirstEnergy Corp.	133		5,328
NextEra Energy, Inc.	46		3,546
NRG Energy, Inc.	118		4,046
PG&E Corp. (a)	336		5,433
Pinnacle West Capital Corp.	54		4,279
PPL Corp.	186		5,169
Public Service Enterprise Group, Inc.	23		1,436
Sempra Energy	12		1,814
Southern Co.	31		2,157
WEC Energy Group, Inc.	100		9,479
Xcel Energy, Inc.	86		5,800
		$	117,004
Electrical Components & Equipment — 0.27%
AMETEK, Inc.	68		9,882
Emerson Electric Co.	78		6,797
		$	16,679
Electronics — 1.36%
Agilent Technologies, Inc.	68		9,407
Allegion PLC	95		10,139
Amphenol Corp., Class A	146		11,931
Fortive Corp.	79		5,385
Garmin Ltd.	41		4,138
Honeywell International, Inc.	64		12,232
Keysight Technologies, Inc. (a)	49		7,913
Mettler-Toledo International, Inc. (a)	6		9,181
TE Connectivity Ltd.	92		12,066
		$	82,392
Energy — Alternate Sources — 0.12%
Enphase Energy, Inc. (a)	17		3,575
First Solar, Inc. (a)	18		3,915
		$	7,490
Engineering & Construction — 0.14%
Jacobs Solutions, Inc.	71		8,343

See accompanying notes.

60

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Entertainment — 0.07%
Live Nation Entertainment, Inc. (a)	58	$	4,060
Environmental Control — 0.33%
Pentair PLC	133		7,351
Republic Services, Inc.	38		5,138
Waste Management, Inc.	46		7,506
		$	19,995
Food — 1.90%
Campbell Soup Co.	151		8,302
Conagra Brands, Inc.	129		4,845
General Mills, Inc.	212		18,118
Hershey Co.	42		10,685
Hormel Foods Corp.	105		4,187
J M Smucker Co.	31		4,878
Kellogg Co.	180		12,053
Kraft Heinz Co.	149		5,762
Kroger Co.	211		10,417
Lamb Weston Holdings, Inc.	74		7,735
McCormick & Co., Inc.	16		1,331
Mondelez International, Inc., Class A	148		10,319
Sysco Corp.	144		11,121
Tyson Foods, Inc., Class A	93		5,517
		$	115,270
Forest Products & Paper — 0.07%
International Paper Co.	114		4,111
Gas — 0.19%
Atmos Energy Corp.	69		7,753
NiSource, Inc.	144		4,026
		$	11,779
Hand/Machine Tools — 0.20%
Snap-on, Inc.	49		12,098
Healthcare — Products — 2.15%
Abbott Laboratories	156		15,797
Bio-Techne Corp.	40		2,968
Boston Scientific Corp. (a)	174		8,705
Danaher Corp.	44		11,090
Edwards Lifesciences Corp. (a)	60		4,964
GE HealthCare Technologies, Inc. (a)	116		9,515
Hologic, Inc. (a)	115		9,280
IDEXX Laboratories, Inc. (a)	19		9,501
Insulet Corp. (a)	12		3,828
Medtronic PLC	33		2,660
ResMed, Inc.	26		5,694
Stryker Corp.	53		15,130
Thermo Fisher Scientific, Inc.	33		19,020
Waters Corp. (a)	11		3,406
West Pharmaceutical Services, Inc.	11		3,811
Zimmer Biomet Holdings, Inc.	41		5,297
		$	130,666
Healthcare — Services — 3.08%
Catalent, Inc. (a)	43		2,826
Centene Corp. (a)	103		6,511
Charles River Laboratories International, Inc. (a)	34		6,862

See accompanying notes.

61

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Healthcare — Services (continued)
DaVita, Inc. (a)	47	$	3,812
Elevance Health, Inc.	43		19,772
HCA Healthcare, Inc.	53		13,975
Humana, Inc.	40		19,418
IQVIA Holdings, Inc. (a)	48		9,547
Laboratory Corp. of America Holdings	26		5,965
Molina Healthcare, Inc. (a)	31		8,292
Quest Diagnostics, Inc.	38		5,376
UnitedHealth Group, Inc.	164		77,505
Universal Health Services, Inc., Class B	55		6,990
		$	186,851
Home Builders — 0.78%
DR Horton, Inc.	134		13,091
Lennar Corp., Class A	119		12,508
NVR, Inc. (a)	2		11,144
PulteGroup, Inc.	181		10,549
		$	47,292
Home Furnishings — 0.06%
Whirlpool Corp.	29		3,828
Household Products — 0.85%
Colgate-Palmolive Co.	182		13,677
Procter & Gamble Co.	256		38,065
		$	51,742
Household Products/Wares — 0.55%
Avery Dennison Corp.	66		11,809
Church & Dwight Co., Inc.	53		4,686
Clorox Co.	31		4,906
Kimberly-Clark Corp.	87		11,677
		$	33,078
Insurance — 3.92%
Aflac, Inc.	178		11,485
Allstate Corp.	46		5,097
American International Group, Inc.	110		5,540
Aon PLC, Class A	44		13,873
Arch Capital Group Ltd. (a)	129		8,755
Arthur J Gallagher & Co.	58		11,096
Assurant, Inc.	29		3,482
Berkshire Hathaway, Inc., Class B (a)	187		57,740
Brown & Brown, Inc.	143		8,211
Chubb Ltd.	52		10,097
Everest Re Group Ltd.	22		7,876
Globe Life, Inc.	102		11,222
Hartford Financial Services Group, Inc.	143		9,966
Lincoln National Corp.	167		3,752
Loews Corp.	90		5,222
Marsh & McLennan Cos., Inc.	54		8,994
MetLife, Inc.	123		7,127
Progressive Corp.	121		17,310
Prudential Financial, Inc.	63		5,213
Travelers Cos., Inc.	71		12,170
W R Berkley Corp.	132		8,218

See accompanying notes.

62

Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Insurance (continued)
Willis Towers Watson PLC	24	$	5,577
		$	238,023
Internet — 8.55%
Alphabet, Inc., Class A (a)	1,046		108,502
Alphabet, Inc., Class C (a)	911		94,744
Amazon.com, Inc. (a)	1,565		161,649
Booking Holdings, Inc. (a)	6		15,914
CDW Corp.	70		13,642
Expedia Group, Inc. (a)	41		3,978
F5, Inc. (a)	26		3,788
Gen Digital, Inc.	231		3,964
Meta Platforms, Inc., Class A (a)	391		82,869
Netflix, Inc. (a)	62		21,420
VeriSign, Inc. (a)	40		8,453
		$	518,923
Iron & Steel — 0.44%
Nucor Corp.	97		14,984
Steel Dynamics, Inc.	102		11,532
		$	26,516
Leisure Time — 0.06%
Royal Caribbean Cruises Ltd. (a)	55		3,591
Lodging — 0.61%
Hilton Worldwide Holdings, Inc.	44		6,198
Las Vegas Sands Corp. (a)	68		3,907
Marriott International, Inc., Class A	94		15,608
MGM Resorts International (a)	179		7,951
Wynn Resorts Ltd. (a)	30		3,357
		$	37,021
Machinery — Construction & Mining — 0.31%
Caterpillar, Inc.	82		18,765
Machinery — Diversified — 1.31%
Deere & Co.	64		26,424
Dover Corp.	59		8,964
IDEX Corp.	36		8,317
Ingersoll Rand, Inc.	70		4,073
Nordson Corp.	14		3,112
Otis Worldwide Corp.	74		6,246
Rockwell Automation, Inc.	30		8,803
Westinghouse Air Brake Technologies Corp.	95		9,601
Xylem, Inc.	36		3,769
		$	79,309
Media — 1.09%
Charter Communications, Inc., Class A (a)	27		9,655
Comcast Corp., Class A	410		15,543
DISH Network Corp., Class A (a)	390		3,639
FactSet Research Systems, Inc.	19		7,887
Fox Corp., Class A	230		7,832
Fox Corp., Class B	146		4,571
News Corp., Class A	224		3,868
News Corp., Class B	205		3,573
Paramount Global, Class B	189		4,217

See accompanying notes.

63

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Media (continued)
Warner Bros Discovery, Inc. (a)	354	$	5,345
		$	66,130
Mining — 0.11%
Freeport-McMoRan, Inc.	163		6,668
Miscellaneous Manufacturers — 1.30%
3M Co.	128		13,454
A O Smith Corp.	48		3,319
Eaton Corp. PLC	48		8,224
General Electric Co.	180		17,208
Illinois Tool Works, Inc.	58		14,120
Parker-Hannifin Corp.	16		5,378
Teledyne Technologies, Inc. (a)	19		8,500
Textron, Inc.	123		8,688
		$	78,891
Oil & Gas — 4.40%
APA Corp.	114		4,111
Chevron Corp.	270		44,053
ConocoPhillips	191		18,949
Coterra Energy, Inc.	319		7,828
Devon Energy Corp.	106		5,365
Diamondback Energy, Inc.	65		8,786
EOG Resources, Inc.	114		13,068
EQT Corp.	127		4,053
Exxon Mobil Corp.	723		79,284
Hess Corp.	37		4,897
Marathon Oil Corp.	316		7,571
Marathon Petroleum Corp.	137		18,472
Occidental Petroleum Corp.	96		5,993
Phillips 66	161		16,322
Pioneer Natural Resources Co.	55		11,233
Valero Energy Corp.	124		17,310
		$	267,295
Oil & Gas Services — 0.19%
Halliburton Co.	160		5,062
Schlumberger Ltd.	137		6,727
		$	11,789
Packaging & Containers — 0.52%
Amcor PLC	1,095		12,461
Packaging Corp. of America	60		8,330
Sealed Air Corp.	147		6,749
Westrock Co.	128		3,900
		$	31,440
Pharmaceuticals — 6.41%
AbbVie, Inc.	369		58,808
AmerisourceBergen Corp.	87		13,930
Becton Dickinson & Co.	58		14,357
Bristol-Myers Squibb Co.	356		24,674
Cardinal Health, Inc.	130		9,815
Cigna Group	64		16,354
CVS Health Corp.	147		10,924
Dexcom, Inc. (a)	83		9,643
Eli Lilly & Co.	138		47,392

See accompanying notes.

64

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Pharmaceuticals (continued)
Henry Schein, Inc. (a)	62	$	5,055
Johnson & Johnson	308		47,740
McKesson Corp.	51		18,159
Merck & Co., Inc.	533		56,706
Organon & Co.	163		3,834
Pfizer, Inc.	848		34,598
Viatris, Inc.	1,081		10,399
Zoetis, Inc.	39		6,491
		$	388,879
Pipelines — 0.51%
Kinder Morgan, Inc.	649		11,364
ONEOK, Inc.	153		9,722
Targa Resources Corp.	60		4,377
Williams Cos., Inc.	193		5,763
		$	31,226
Real Estate — 0.08%
CBRE Group, Inc., Class A (a)	65		4,733
REITs — 1.68%
AvalonBay Communities, Inc.	30		5,042
Boston Properties, Inc.	74		4,005
Camden Property Trust	37		3,879
Crown Castle, Inc.	41		5,487
Equinix, Inc.	17		12,258
Equity Residential	21		1,260
Extra Space Storage, Inc.	22		3,585
Federal Realty Investment Trust	10		988
Host Hotels & Resorts, Inc.	259		4,271
Iron Mountain, Inc.	131		6,931
Mid-America Apartment Communities, Inc.	28		4,229
Prologis, Inc.	69		8,609
Public Storage	22		6,647
Realty Income Corp.	102		6,459
Regency Centers Corp.	64		3,916
SBA Communications Corp.	14		3,655
Simon Property Group, Inc.	92		10,301
VICI Properties, Inc.	184		6,002
Weyerhaeuser Co.	156		4,700
		$	102,224
Retail — 4.98%
Advance Auto Parts, Inc.	34		4,135
AutoZone, Inc. (a)	7		17,207
Bath & Body Works, Inc.	100		3,658
Best Buy Co., Inc.	56		4,383
CarMax, Inc. (a)	64		4,114
Chipotle Mexican Grill, Inc. (a)	6		10,250
Costco Wholesale Corp.	37		18,384
Darden Restaurants, Inc.	58		8,999
Dollar General Corp.	57		11,996
Dollar Tree, Inc. (a)	63		9,044
Genuine Parts Co.	83		13,887
Home Depot, Inc.	156		46,039
Lowe's Cos., Inc.	50		9,998
McDonald's Corp.	65		18,175
O'Reilly Automotive, Inc. (a)	22		18,677

See accompanying notes.

65

	Schedule of Investments
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Retail (continued)
Ross Stores, Inc.	58	$	6,155
Starbucks Corp.	115		11,975
TJX Cos., Inc.	127		9,952
Tractor Supply Co.	39		9,167
Ulta Beauty, Inc. (a)	27		14,733
Walmart, Inc.	309		45,562
Yum! Brands, Inc.	46		6,076
		$	302,566
Semiconductors — 5.68%
Analog Devices, Inc.	79		15,580
Applied Materials, Inc.	136		16,705
Broadcom, Inc.	54		34,643
KLA Corp.	44		17,564
Lam Research Corp.	38		20,145
Microchip Technology, Inc.	190		15,918
Micron Technology, Inc.	112		6,758
Monolithic Power Systems, Inc.	15		7,508
NVIDIA Corp.	432		119,997
NXP Semiconductors NV	87		16,223
ON Semiconductor Corp. (a)	176		14,488
Qorvo, Inc. (a)	39		3,961
QUALCOMM, Inc.	165		21,051
Skyworks Solutions, Inc.	66		7,787
Texas Instruments, Inc.	142		26,413
		$	344,741
Shipbuilding — 0.13%
Huntington Ingalls Industries, Inc.	39		8,074
Software — 8.57%
Activision Blizzard, Inc.	92		7,874
Adobe, Inc. (a)	30		11,561
Akamai Technologies, Inc. (a)	52		4,072
ANSYS, Inc. (a)	25		8,320
Autodesk, Inc. (a)	22		4,580
Broadridge Financial Solutions, Inc.	31		4,544
Cadence Design Systems, Inc. (a)	52		10,925
Ceridian HCM Holding, Inc. (a)	47		3,441
Electronic Arts, Inc.	43		5,179
Fair Isaac Corp. (a)	5		3,514
Fiserv, Inc. (a)	112		12,659
Intuit, Inc.	20		8,917
Jack Henry & Associates, Inc.	20		3,014
Microsoft Corp.	1,306		376,520
MSCI, Inc.	18		10,075
Oracle Corp.	147		13,659
Paychex, Inc.	51		5,844
Paycom Software, Inc. (a)	11		3,344
PTC, Inc. (a)	35		4,488
Roper Technologies, Inc.	15		6,610
Synopsys, Inc. (a)	29		11,201
		$	520,341
Telecommunications — 1.98%
Arista Networks, Inc. (a)	56		9,400
AT&T, Inc.	690		13,283
Cisco Systems, Inc.	899		46,995

See accompanying notes.

66

		Schedule of Investments
	Principal U.S. Large-Cap Adaptive Multi-Factor ETF
		March 31, 2023 (unaudited)
COMMON STOCKS (continued)		Shares Held			Value
Telecommunications (continued)
Corning, Inc.		38		$	1,341
Juniper Networks, Inc.		30			1,033
Motorola Solutions, Inc.		41			11,731
T-Mobile U.S., Inc. (a)		67			9,704
Verizon Communications, Inc.		680			26,445
				$	119,932
Transportation — 1.76%
CH Robinson Worldwide, Inc.		82			8,148
CSX Corp.		485			14,521
Expeditors International of Washington, Inc.		103			11,342
FedEx Corp.		51			11,653
JB Hunt Transport Services, Inc.		42			7,369
Norfolk Southern Corp.		59			12,508
Old Dominion Freight Line, Inc.		24			8,180
Union Pacific Corp.		45			9,057
United Parcel Service, Inc., Class B		125			24,249
				$	107,027
Water — 0.08%
American Water Works Co., Inc.		35			5,127
TOTAL COMMON STOCKS				$	6,025,190
INVESTMENT COMPANIES — 0.34%		Shares Held			Value
Money Market Fund — 0.34%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (b)		20,769		$	20,769
TOTAL INVESTMENT COMPANIES				$	20,769
Total Investments				$	6,045,959
Other Assets and Liabilities — 0.41%					24,766
Total Net Assets — 100.00%				$	6,070,725
(a)	Non-income producing security.
(b)	Current yield shown is as of period end.
	Portfolio Summary
Sector		Percent
Technology		22.82	%
Consumer, Non-cyclical		20.77	%
Financial		13.10	%
Communications		12.03	%
Consumer, Cyclical		10.61	%
Industrial		9.97	%
Energy		5.24	%
Basic Materials		2.50	%
Utilities		2.21	%
Money Market Fund		0.34	%
Other Assets and Liabilities		0.41	%
TOTAL NET ASSETS		100.00	%
See accompanying notes.		67

	Schedule of Investments
	Principal U.S. Mega-Cap ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 99.59%		Shares Held		Value
Auto Manufacturers — 1.92%
Tesla, Inc. (a)		107,950	$	22,395,307
Banks — 4.65%
Bank of America Corp.		663,092		18,964,431
JPMorgan Chase & Co.		189,322		24,670,550
Wells Fargo & Co.		284,056		10,618,013
			$	54,252,994
Beverages — 3.34%
Coca-Cola Co.		412,390		25,580,552
PepsiCo, Inc.		73,583		13,414,181
			$	38,994,733
Chemicals — 2.45%
Linde PLC		80,263		28,528,681
Computers — 10.07%
Accenture PLC, Class A		124,411		35,557,908
Apple, Inc.		496,045		81,797,820
			$	117,355,728
Diversified Financial Services — 6.86%
Mastercard, Inc., Class A		110,914		40,307,257
Visa, Inc., Class A		176,171		39,719,513
			$	80,026,770
Healthcare — Products — 7.38%
Abbott Laboratories		243,451		24,651,848
Danaher Corp.		137,118		34,559,221
Thermo Fisher Scientific, Inc.		46,590		26,853,078
			$	86,064,147
Healthcare — Services — 2.55%
UnitedHealth Group, Inc.		62,835		29,695,193
Household Products — 2.30%
Procter & Gamble Co.		179,984		26,761,821
Insurance — 1.19%
Berkshire Hathaway, Inc., Class B (a)		45,079		13,919,043
Internet — 9.34%
Alphabet, Inc., Class A (a)		331,629		34,399,876
Amazon.com, Inc. (a)		193,162		19,951,703
Meta Platforms, Inc., Class A (a)		257,661		54,608,672
			$	108,960,251
Media — 1.07%
Walt Disney Co. (a)		124,798		12,496,024
Oil & Gas — 5.50%
Chevron Corp.		133,633		21,803,560
ConocoPhillips		185,291		18,382,720
Exxon Mobil Corp.		218,640		23,976,063
			$	64,162,343
Pharmaceuticals — 12.76%
AbbVie, Inc.		228,053		36,344,807
Bristol-Myers Squibb Co.		319,495		22,144,199
Eli Lilly & Co.		37,369		12,833,262

See accompanying notes.

68

		Schedule of Investments
		Principal U.S. Mega-Cap ETF
		March 31, 2023 (unaudited)
COMMON STOCKS (continued)				Shares Held		Value
Pharmaceuticals (continued)
Johnson & Johnson				137,156	$	21,259,180
Merck & Co., Inc.				241,903		25,736,060
Pfizer, Inc.				746,108		30,441,206
					$	148,758,714
Retail — 5.61%
Costco Wholesale Corp.				48,408		24,052,483
Home Depot, Inc.				46,232		13,643,988
McDonald's Corp.				50,029		13,988,609
Walmart, Inc.				93,078		13,724,351
					$	65,409,431
Semiconductors — 11.55%
Broadcom, Inc.				51,530		33,058,556
NVIDIA Corp.				268,803		74,665,409
Texas Instruments, Inc.				144,889		26,950,803
					$	134,674,768
Software — 7.42%
Microsoft Corp.				244,892		70,602,364
Salesforce, Inc. (a)				79,503		15,883,109
					$	86,485,473
Telecommunications — 3.63%
Cisco Systems, Inc.				541,471		28,305,397
Verizon Communications, Inc.				360,232		14,009,422
					$	42,314,819
TOTAL COMMON STOCKS					$	1,161,256,240
INVESTMENT COMPANIES — 0.35%				Shares Held		Value
Money Market Fund — 0.35%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (b)				4,073,542	$	4,073,542
TOTAL INVESTMENT COMPANIES					$	4,073,542
Total Investments					$	1,165,329,782
Other Assets and Liabilities — 0.06%						708,404
Total Net Assets — 100.00%					$	1,166,038,186
(a)	Non-income producing security.
(b)	Current yield shown is as of period end.
	Portfolio Summary
Sector		Percent
Technology		29.03	%
Consumer, Non-cyclical		28.32	%
Communications		14.05	%
Financial		12.71	%
Consumer, Cyclical		7.53	%
Energy		5.50	%
Basic Materials		2.45	%
Money Market Fund		0.35	%
Other Assets and Liabilities		0.06	%
TOTAL NET ASSETS		100.00	%
See accompanying notes.		69

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 99.18%	Shares Held		Value
Aerospace & Defense — 1.20%
AAR Corp. (a)	265	$	14,456
Aerojet Rocketdyne Holdings, Inc. (a)	261		14,661
Barnes Group, Inc.	229		9,224
Moog, Inc., Class A	195		19,646
National Presto Industries, Inc.	69		4,974
Triumph Group, Inc. (a)	464		5,378
		$	68,339
Agriculture — 0.58%
Andersons, Inc.	274		11,322
Fresh Del Monte Produce, Inc.	387		11,652
Universal Corp.	35		1,851
Vector Group Ltd.	669		8,035
		$	32,860
Airlines — 0.11%
SkyWest, Inc. (a)	287		6,363
Apparel — 1.31%
Kontoor Brands, Inc.	471		22,792
Oxford Industries, Inc.	175		18,478
Steven Madden Ltd.	748		26,928
Urban Outfitters, Inc. (a)	226		6,265
		$	74,463
Auto Manufacturers — 0.28%
Wabash National Corp.	655		16,107
Auto Parts & Equipment — 1.32%
American Axle & Manufacturing Holdings, Inc. (a)	1,318		10,294
Dorman Products, Inc. (a)	116		10,006
Methode Electronics, Inc.	472		20,711
Standard Motor Products, Inc.	405		14,948
Titan International, Inc. (a)	795		8,332
XPEL, Inc. (a)	163		11,076
		$	75,367
Banks — 10.06%
Ameris Bancorp	618		22,606
Atlantic Union Bankshares Corp.	540		18,927
BancFirst Corp.	88		7,313
Bancorp, Inc. (a)	201		5,598
BankUnited, Inc.	301		6,797
Banner Corp.	400		21,748
Central Pacific Financial Corp.	520		9,308
City Holding Co.	137		12,451
Community Bank System, Inc.	202		10,603
Customers Bancorp, Inc. (a)	458		8,482
CVB Financial Corp.	825		13,761
Dime Community Bancshares, Inc.	390		8,861
Eagle Bancorp, Inc.	348		11,648
FB Financial Corp.	386		11,997
First BanCorp	1,443		16,479
First Bancorp/Southern Pines NC	375		13,320
First Commonwealth Financial Corp.	1,016		12,629
First Financial Bancorp	705		15,348
First Hawaiian, Inc.	534		11,016
Hanmi Financial Corp.	519		9,638

See accompanying notes.

70

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Banks (continued)
Heritage Financial Corp.	678	$	14,509
Hilltop Holdings, Inc.	453		13,441
HomeStreet, Inc.	230		4,138
Hope Bancorp, Inc.	1,231		12,088
Independent Bank Corp.	305		20,014
Independent Bank Group, Inc.	312		14,461
Lakeland Financial Corp.	122		7,642
National Bank Holdings Corp., Class A	231		7,729
NBT Bancorp, Inc.	560		18,878
OFG Bancorp	489		12,196
Park National Corp.	67		7,944
Pathward Financial, Inc.	116		4,813
Preferred Bank	191		10,469
Renasant Corp.	677		20,703
S&T Bancorp, Inc.	560		17,612
Seacoast Banking Corp. of Florida	269		6,375
ServisFirst Bancshares, Inc.	142		7,757
Simmons First National Corp., Class A	570		9,969
Southside Bancshares, Inc.	343		11,388
Stellar Bancorp, Inc.	254		6,251
Tompkins Financial Corp.	229		15,162
Triumph Financial, Inc. (a)	86		4,993
TrustCo Bank Corp. NY	316		10,093
Trustmark Corp.	562		13,881
United Community Banks, Inc.	759		21,343
Veritex Holdings, Inc.	525		9,586
Walker & Dunlop, Inc.	203		15,463
Westamerica BanCorp	148		6,556
		$	573,984
Beverages — 0.44%
MGP Ingredients, Inc.	137		13,251
National Beverage Corp. (a)	230		12,125
		$	25,376
Biotechnology — 1.21%
ANI Pharmaceuticals, Inc. (a)	108		4,290
Certara, Inc. (a)	322		7,764
Dynavax Technologies Corp. (a)	1,079		10,585
Innoviva, Inc. (a)	913		10,271
iTeos Therapeutics, Inc. (a)	307		4,178
Ligand Pharmaceuticals, Inc. (a)	72		5,296
NeoGenomics, Inc. (a)	412		7,173
Vir Biotechnology, Inc. (a)	576		13,404
Xencor, Inc. (a)	218		6,080
		$	69,041
Chemicals — 3.00%
AdvanSix, Inc.	322		12,323
American Vanguard Corp.	640		14,003
AZZ, Inc.	253		10,434
Balchem Corp.	110		13,913
Hawkins, Inc.	136		5,954
HB Fuller Co.	190		13,006
Innospec, Inc.	176		18,070
Koppers Holdings, Inc.	322		11,260
Livent Corp. (a)	467		10,143
Mativ Holdings, Inc.	523		11,229

See accompanying notes.

71

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Chemicals (continued)
Minerals Technologies, Inc.	163	$	9,848
Quaker Chemical Corp.	81		16,034
Rogers Corp. (a)	54		8,825
Stepan Co.	158		16,279
		$	171,321
Coal — 0.80%
CONSOL Energy, Inc.	353		20,569
SunCoke Energy, Inc.	1,245		11,180
Warrior Met Coal, Inc.	376		13,803
		$	45,552
Commercial Services — 5.56%
Aaron's Co., Inc.	445		4,299
ABM Industries, Inc.	648		29,121
Adtalem Global Education, Inc. (a)	380		14,676
Alarm.com Holdings, Inc. (a)	198		9,955
AMN Healthcare Services, Inc. (a)	237		19,661
CoreCivic, Inc. (a)	1,157		10,644
CorVel Corp. (a)	43		8,182
Cross Country Healthcare, Inc. (a)	604		13,481
Deluxe Corp.	316		5,056
EVERTEC, Inc.	505		17,044
Forrester Research, Inc. (a)	106		3,429
GEO Group, Inc. (a)	1,904		15,023
Green Dot Corp., Class A (a)	563		9,672
Healthcare Services Group, Inc. (a)	368		5,104
Heidrick & Struggles International, Inc.	288		8,744
Kelly Services, Inc., Class A	85		1,410
Korn Ferry	375		19,402
Matthews International Corp., Class A	191		6,887
Medifast, Inc.	104		10,782
Mister Car Wash, Inc. (a)	472		4,069
Monro, Inc.	292		14,434
Payoneer Global, Inc. (a)	865		5,432
Perdoceo Education Corp. (a)	874		11,738
PROG Holdings, Inc. (a)	472		11,229
Resources Connection, Inc.	722		12,317
Strategic Education, Inc.	102		9,163
Stride, Inc. (a)	468		18,369
TrueBlue, Inc. (a)	347		6,177
Upbound Group, Inc.	466		11,422
		$	316,922
Computers — 1.01%
Corsair Gaming, Inc. (a)	250		4,587
Insight Enterprises, Inc. (a)	261		37,313
NetScout Systems, Inc. (a)	77		2,206
OneSpan, Inc. (a)	238		4,165
TTEC Holdings, Inc.	244		9,084
		$	57,355
Construction Materials — 2.35%
AAON, Inc.	219		21,175
American Woodmark Corp. (a)	278		14,475
Apogee Enterprises, Inc.	271		11,721
Boise Cascade Co.	292		18,469
Gibraltar Industries, Inc. (a)	413		20,031

See accompanying notes.

72

Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Construction Materials (continued)
Griffon Corp.	188	$	6,018
Masterbrand, Inc. (a)	1,382		11,111
PGT Innovations, Inc. (a)	752		18,883
SPX Technologies, Inc. (a)	173		12,210
		$	134,093
Distribution/Wholesale — 0.70%
G-III Apparel Group Ltd. (a)	330		5,131
Resideo Technologies, Inc. (a)	910		16,635
ScanSource, Inc. (a)	361		10,989
Veritiv Corp.	54		7,298
		$	40,053
Diversified Financial Services — 2.94%
Avantax, Inc. (a)	257		6,764
Bread Financial Holdings, Inc.	221		6,701
Brightsphere Investment Group, Inc.	462		10,894
Encore Capital Group, Inc. (a)	160		8,072
Enova International, Inc. (a)	274		12,174
EZCORP, Inc., Class A (a)	1,551		13,339
LendingTree, Inc. (a)	160		4,266
Mr Cooper Group, Inc. (a)	486		19,911
Piper Sandler Cos.	64		8,871
PRA Group, Inc. (a)	197		7,675
Radian Group, Inc.	1,453		32,111
StoneX Group, Inc. (a)	193		19,981
Virtus Investment Partners, Inc.	35		6,664
WisdomTree, Inc.	985		5,772
World Acceptance Corp. (a)	51		4,248
		$	167,443
Electric — 0.91%
Avista Corp.	280		11,886
Otter Tail Corp.	404		29,197
Unitil Corp.	192		10,952
		$	52,035
Electrical Components & Equipment — 0.72%
Encore Wire Corp.	157		29,097
Insteel Industries, Inc.	303		8,429
Powell Industries, Inc.	90		3,833
		$	41,359
Electronics — 3.19%
Advanced Energy Industries, Inc.	231		22,638
Badger Meter, Inc.	184		22,415
Benchmark Electronics, Inc.	670		15,872
Brady Corp., Class A	328		17,623
Comtech Telecommunications Corp.	299		3,731
CTS Corp.	286		14,146
Itron, Inc. (a)	142		7,874
OSI Systems, Inc. (a)	137		14,023
Plexus Corp. (a)	191		18,636
Sanmina Corp. (a)	541		32,996
TTM Technologies, Inc. (a)	871		11,750
		$	181,704

See accompanying notes.

73

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Energy — Alternate Sources — 0.27%
FutureFuel Corp.	1,007	$	7,432
REX American Resources Corp. (a)	280		8,005
		$	15,437
Engineering & Construction — 2.13%
Arcosa, Inc.	322		20,321
Comfort Systems USA, Inc.	298		43,496
Dycom Industries, Inc. (a)	83		7,773
Frontdoor, Inc. (a)	520		14,498
Granite Construction, Inc.	208		8,545
MYR Group, Inc. (a)	169		21,296
NV5 Global, Inc. (a)	51		5,302
		$	121,231
Entertainment — 0.35%
Golden Entertainment, Inc. (a)	130		5,656
Monarch Casino & Resort, Inc.	85		6,303
Six Flags Entertainment Corp. (a)	292		7,799
		$	19,758
Food — 2.33%
Cal-Maine Foods, Inc.	382		23,260
Calavo Growers, Inc.	310		8,919
Chefs' Warehouse, Inc. (a)	197		6,708
Hostess Brands, Inc. (a)	856		21,297
J & J Snack Foods Corp.	65		9,634
John B Sanfilippo & Son, Inc.	115		11,146
Seneca Foods Corp., Class A (a)	102		5,331
Simply Good Foods Co. (a)	306		12,170
SpartanNash Co.	276		6,845
Tootsie Roll Industries, Inc.	229		10,277
TreeHouse Foods, Inc. (a)	208		10,489
United Natural Foods, Inc. (a)	268		7,062
		$	133,138
Forest Products & Paper — 0.50%
Mercer International, Inc.	934		9,130
Sylvamo Corp.	421		19,475
		$	28,605
Gas — 0.41%
Chesapeake Utilities Corp.	73		9,343
Northwest Natural Holding Co.	301		14,316
		$	23,659
Hand/Machine Tools — 0.70%
Enerpac Tool Group Corp.	294		7,497
Franklin Electric Co., Inc.	243		22,866
Kennametal, Inc.	353		9,736
		$	40,099
Healthcare — Products — 1.70%
Avanos Medical, Inc. (a)	435		12,937
BioLife Solutions, Inc. (a)	202		4,393
Cardiovascular Systems, Inc. (a)	228		4,528
Embecta Corp.	226		6,355
Glaukos Corp. (a)	50		2,505

See accompanying notes.

74

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Healthcare — Products (continued)
Integer Holdings Corp. (a)	100	$	7,750
LeMaitre Vascular, Inc.	215		11,066
Merit Medical Systems, Inc. (a)	339		25,069
NuVasive, Inc. (a)	236		9,749
OraSure Technologies, Inc. (a)	651		3,939
Varex Imaging Corp. (a)	67		1,219
Zynex, Inc. (a)	598		7,176
		$	96,686
Healthcare — Services — 1.67%
Addus HomeCare Corp. (a)	135		14,413
Agiliti, Inc. (a)	248		3,963
Community Health Systems, Inc. (a)	1,013		4,964
Enhabit, Inc. (a)	661		9,194
Ensign Group, Inc.	181		17,293
Fulgent Genetics, Inc. (a)	151		4,714
Pediatrix Medical Group, Inc. (a)	405		6,038
RadNet, Inc. (a)	218		5,456
Select Medical Holdings Corp.	654		16,906
U.S. Physical Therapy, Inc.	127		12,435
		$	95,376
Home Builders — 4.18%
Cavco Industries, Inc. (a)	77		24,466
Century Communities, Inc.	210		13,423
Green Brick Partners, Inc. (a)	421		14,760
Installed Building Products, Inc.	216		24,630
LCI Industries	231		25,380
LGI Homes, Inc. (a)	128		14,596
M/I Homes, Inc. (a)	339		21,388
MDC Holdings, Inc.	442		17,181
Meritage Homes Corp.	316		36,896
Tri Pointe Homes, Inc. (a)	1,041		26,358
Winnebago Industries, Inc.	339		19,560
		$	238,638
Home Furnishings — 0.44%
Ethan Allen Interiors, Inc.	523		14,362
iRobot Corp. (a)	38		1,658
Sleep Number Corp. (a)	164		4,987
Xperi, Inc. (a)	364		3,979
		$	24,986
Household Products — 0.86%
Edgewell Personal Care Co.	224		9,502
elf Beauty, Inc. (a)	262		21,576
Inter Parfums, Inc.	127		18,064
		$	49,142
Household Products/Wares — 0.96%
Central Garden & Pet Co. (a)	228		9,361
Central Garden & Pet Co., Class A (a)	373		14,573
Quanex Building Products Corp.	643		13,844
WD-40 Co.	97		17,271
		$	55,049

See accompanying notes.

75

Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Insurance — 2.63%
Ambac Financial Group, Inc. (a)	707	$	10,944
American Equity Investment Life Holding Co.	438		15,983
AMERISAFE, Inc.	132		6,461
Assured Guaranty Ltd.	59		2,966
Employers Holdings, Inc.	163		6,796
Genworth Financial, Inc., Class A (a)	3,746		18,805
Horace Mann Educators Corp.	56		1,875
James River Group Holdings Ltd.	526		10,862
Mercury General Corp.	168		5,332
NMI Holdings, Inc., Class A (a)	994		22,196
Palomar Holdings, Inc. (a)	200		11,040
ProAssurance Corp.	89		1,645
Safety Insurance Group, Inc.	23		1,714
SiriusPoint Ltd. (a)	1,226		9,967
Stewart Information Services Corp.	269		10,854
United Fire Group, Inc.	155		4,115
Universal Insurance Holdings, Inc.	463		8,436
		$	149,991
Internet — 1.24%
Cars.com, Inc. (a)	280		5,404
Cogent Communications Holdings, Inc.	173		11,023
ePlus, Inc. (a)	266		13,045
HealthStream, Inc. (a)	356		9,648
Liquidity Services, Inc. (a)	326		4,293
Perficient, Inc. (a)	140		10,107
QuinStreet, Inc. (a)	289		4,586
Shutterstock, Inc.	83		6,026
TechTarget, Inc. (a)	125		4,515
Yelp, Inc. (a)	77		2,364
		$	71,011
Iron & Steel — 0.50%
ATI, Inc. (a)	322		12,706
Carpenter Technology Corp.	165		7,385
Haynes International, Inc.	164		8,215
		$	28,306
Leisure Time — 0.15%
Vista Outdoor, Inc. (a)	311		8,618
Lodging — 0.17%
Marcus Corp.	591		9,456
Machinery — Construction & Mining — 0.09%
Astec Industries, Inc.	119		4,909
Machinery — Diversified — 1.78%
Alamo Group, Inc.	81		14,917
Albany International Corp., Class A	124		11,081
Applied Industrial Technologies, Inc.	220		31,268
CIRCOR International, Inc. (a)	137		4,263
DXP Enterprises, Inc. (a)	353		9,503
Ichor Holdings Ltd. (a)	314		10,280
Lindsay Corp.	51		7,708
Tennant Co.	185		12,678
		$	101,698

See accompanying notes.

76

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Media — 0.55%
AMC Networks, Inc., Class A (a)	282	$	4,958
EW Scripps Co., Class A (a)	928		8,732
Scholastic Corp.	319		10,916
Thryv Holdings, Inc. (a)	282		6,503
		$	31,109
Metal Fabrication & Hardware — 1.21%
Mueller Industries, Inc.	497		36,520
Olympic Steel, Inc.	168		8,771
Standex International Corp.	110		13,469
TimkenSteel Corp. (a)	274		5,025
Tredegar Corp.	586		5,350
		$	69,135
Mining — 0.14%
Arconic Corp. (a)	303		7,948
Miscellaneous Manufacturers — 2.33%
EnPro Industries, Inc.	24		2,493
ESCO Technologies, Inc.	186		17,754
Fabrinet (a)	219		26,008
Federal Signal Corp.	393		21,305
Hillenbrand, Inc.	257		12,215
John Bean Technologies Corp.	203		22,186
Materion Corp.	129		14,964
Myers Industries, Inc.	657		14,079
Sturm Ruger & Co., Inc.	29		1,666
		$	132,670
Office & Business Equipment — 0.17%
Pitney Bowes, Inc.	2,493		9,698
Office Furnishings — 0.30%
HNI Corp.	449		12,500
Interface, Inc.	567		4,604
		$	17,104
Oil & Gas — 2.59%
Callon Petroleum Co. (a)	398		13,309
Civitas Resources, Inc.	292		19,955
Comstock Resources, Inc.	938		10,121
CVR Energy, Inc.	475		15,570
Nabors Industries Ltd. (a)	50		6,096
Northern Oil & Gas, Inc.	476		14,447
Par Pacific Holdings, Inc. (a)	643		18,776
Patterson-UTI Energy, Inc.	733		8,576
Ranger Oil Corp., Class A	238		9,720
SM Energy Co.	366		10,307
Talos Energy, Inc. (a)	1,029		15,270
Vital Energy, Inc. (a)	117		5,328
		$	147,475
Oil & Gas Services — 1.26%
Archrock, Inc.	570		5,569
Bristow Group, Inc. (a)	214		4,793
DMC Global, Inc. (a)	393		8,634
Dril-Quip, Inc. (a)	175		5,021
Helix Energy Solutions Group, Inc. (a)	683		5,286

See accompanying notes.

77

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Oil & Gas Services (continued)
NexTier Oilfield Solutions, Inc. (a)	786	$	6,249
NOW, Inc. (a)	1,031		11,496
Oceaneering International, Inc. (a)	371		6,541
Oil States International, Inc. (a)	517		4,307
RPC, Inc.	1,126		8,659
U.S. Silica Holdings, Inc. (a)	457		5,456
		$	72,011
Packaging & Containers — 0.67%
Clearwater Paper Corp. (a)	262		8,756
O-I Glass, Inc. (a)	1,301		29,546
		$	38,302
Pharmaceuticals — 2.06%
AdaptHealth Corp. (a)	358		4,450
Amphastar Pharmaceuticals, Inc. (a)	193		7,237
Anika Therapeutics, Inc. (a)	133		3,820
Catalyst Pharmaceuticals, Inc. (a)	710		11,772
Collegium Pharmaceutical, Inc. (a)	188		4,510
Corcept Therapeutics, Inc. (a)	304		6,585
Eagle Pharmaceuticals, Inc. (a)	153		4,340
Harmony Biosciences Holdings, Inc. (a)	123		4,016
Ironwood Pharmaceuticals, Inc. (a)	1,285		13,518
Owens & Minor, Inc. (a)	431		6,271
Pacira BioSciences, Inc. (a)	52		2,122
Phibro Animal Health Corp., Class A	544		8,334
Prestige Consumer Healthcare, Inc. (a)	324		20,292
Supernus Pharmaceuticals, Inc. (a)	248		8,985
uniQure NV (a)	226		4,552
USANA Health Sciences, Inc. (a)	103		6,479
		$	117,283
Real Estate — 0.47%
Alexander & Baldwin, Inc. (a)	100		1,891
Cushman & Wakefield PLC (a)	668		7,041
Douglas Elliman, Inc.	1,312		4,080
Kennedy-Wilson Holdings, Inc.	134		2,223
Marcus & Millichap, Inc.	49		1,573
RE/MAX Holdings, Inc., Class A	433		8,123
St. Joe Co.	47		1,956
		$	26,887
REITs — 5.48%
Acadia Realty Trust	133		1,855
American Assets Trust, Inc.	89		1,655
Apollo Commercial Real Estate Finance, Inc.	1,172		10,911
Armada Hoffler Properties, Inc.	939		11,090
ARMOUR Residential REIT, Inc.	1,193		6,263
Brandywine Realty Trust	1,159		5,482
CareTrust REIT, Inc.	461		9,026
Centerspace	27		1,475
Chatham Lodging Trust	131		1,374
Community Healthcare Trust, Inc.	171		6,259
DiamondRock Hospitality Co.	1,136		9,236
Easterly Government Properties, Inc.	514		7,062
Ellington Financial, Inc.	125		1,526
Elme Communities	102		1,822
Essential Properties Realty Trust, Inc.	901		22,390

See accompanying notes.

78

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
REITs (continued)
Four Corners Property Trust, Inc.	621	$	16,680
Franklin BSP Realty Trust, Inc.	554		6,609
Getty Realty Corp.	377		13,583
Global Net Lease, Inc.	583		7,497
Hudson Pacific Properties, Inc.	863		5,739
Innovative Industrial Properties, Inc.	87		6,611
iStar, Inc. (a)	103		3,025
JBG SMITH Properties	130		1,958
KKR Real Estate Finance Trust, Inc.	127		1,447
LTC Properties, Inc.	377		13,244
LXP Industrial Trust	271		2,794
NexPoint Residential Trust, Inc.	33		1,441
Office Properties Income Trust	402		4,945
Orion Office REIT, Inc.	201		1,347
PennyMac Mortgage Investment Trust	139		1,714
Ready Capital Corp.	1,167		11,868
Redwood Trust, Inc.	205		1,382
Retail Opportunity Investments Corp.	592		8,264
RPT Realty	719		6,838
Saul Centers, Inc.	132		5,148
Service Properties Trust	1,335		13,297
SITE Centers Corp.	191		2,346
Summit Hotel Properties, Inc.	750		5,250
Sunstone Hotel Investors, Inc.	241		2,381
Tanger Factory Outlet Centers, Inc.	473		9,285
Two Harbors Investment Corp.	962		14,151
Uniti Group, Inc.	1,504		5,339
Universal Health Realty Income Trust	194		9,333
Urban Edge Properties	143		2,154
Urstadt Biddle Properties, Inc., Class A	513		9,014
Veris Residential, Inc. (a)	485		7,100
Whitestone REIT	537		4,940
Xenia Hotels & Resorts, Inc.	657		8,600
		$	312,750
Retail — 8.76%
Abercrombie & Fitch Co., Class A (a)	213		5,911
Academy Sports & Outdoors, Inc.	581		37,910
America's Car-Mart, Inc. (a)	111		8,792
American Eagle Outfitters, Inc.	609		8,185
Asbury Automotive Group, Inc. (a)	170		35,700
BJ's Restaurants, Inc. (a)	147		4,284
Bloomin' Brands, Inc.	684		17,545
Boot Barn Holdings, Inc. (a)	93		7,128
Brinker International, Inc. (a)	347		13,186
Buckle, Inc.	320		11,421
Caleres, Inc.	443		9,582
Cheesecake Factory, Inc.	179		6,274
Chico's FAS, Inc. (a)	1,703		9,367
Children's Place, Inc. (a)	120		4,830
Chuy's Holdings, Inc. (a)	160		5,736
Cracker Barrel Old Country Store, Inc.	89		10,110
Dave & Buster's Entertainment, Inc. (a)	336		12,361
Designer Brands, Inc., Class A	513		4,484
Dine Brands Global, Inc.	181		12,243
El Pollo Loco Holdings, Inc.	429		4,114
Genesco, Inc. (a)	224		8,261
GMS, Inc. (a)	450		26,051

See accompanying notes.

79

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Retail (continued)
Group 1 Automotive, Inc.	125	$	28,303
Guess?, Inc.	330		6,422
Haverty Furniture Cos., Inc.	411		13,115
Hibbett, Inc.	228		13,447
Jack in the Box, Inc.	84		7,358
La-Z-Boy, Inc.	568		16,517
Leslie's, Inc. (a)	534		5,879
MarineMax, Inc. (a)	311		8,941
Movado Group, Inc.	159		4,574
Nu Skin Enterprises, Inc., Class A	55		2,162
ODP Corp. (a)	342		15,383
Patrick Industries, Inc.	288		19,817
PC Connection, Inc.	190		8,542
PriceSmart, Inc.	213		15,225
Ruth's Hospitality Group, Inc.	305		5,008
Sally Beauty Holdings, Inc. (a)	838		13,056
Shoe Carnival, Inc.	323		8,285
Signet Jewelers Ltd.	135		10,500
Sonic Automotive, Inc., Class A	191		10,379
World Fuel Services Corp.	733		18,728
Zumiez, Inc. (a)	233		4,297
		$	499,413
Savings & Loans — 2.55%
Axos Financial, Inc. (a)	375		13,845
Banc of California, Inc.	818		10,250
Berkshire Hills Bancorp, Inc.	492		12,330
Brookline Bancorp, Inc.	1,070		11,235
Capitol Federal Financial, Inc.	213		1,433
Northfield Bancorp, Inc.	1,089		12,828
Northwest Bancshares, Inc.	1,081		13,004
Pacific Premier Bancorp, Inc.	707		16,982
Provident Financial Services, Inc.	699		13,407
Washington Federal, Inc.	750		22,590
WSFS Financial Corp.	459		17,263
		$	145,167
Semiconductors — 2.56%
Alpha & Omega Semiconductor Ltd. (a)	180		4,851
Axcelis Technologies, Inc. (a)	168		22,386
Cohu, Inc. (a)	227		8,715
Diodes, Inc. (a)	240		22,262
Kulicke & Soffa Industries, Inc.	334		17,598
MaxLinear, Inc. (a)	209		7,359
Onto Innovation, Inc. (a)	125		10,985
Photronics, Inc. (a)	616		10,213
Rambus, Inc. (a)	356		18,249
Semtech Corp. (a)	435		10,501
SMART Global Holdings, Inc. (a)	317		5,465
Veeco Instruments, Inc. (a)	346		7,311
		$	145,895
Software — 2.90%
Adeia, Inc.	1,738		15,399
Agilysys, Inc. (a)	74		6,106
Avid Technology, Inc. (a)	153		4,893
Computer Programs & Systems, Inc. (a)	311		9,392
Consensus Cloud Solutions, Inc. (a)	146		4,977

See accompanying notes.

80

	Schedule of Investments
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Software (continued)
CSG Systems International, Inc.	147	$	7,894
Digi International, Inc. (a)	359		12,091
Digital Turbine, Inc. (a)	484		5,982
Donnelley Financial Solutions, Inc. (a)	262		10,705
DoubleVerify Holdings, Inc. (a)	471		14,201
Ebix, Inc.	575		7,584
NextGen Healthcare, Inc. (a)	349		6,076
PDF Solutions, Inc. (a)	128		5,427
Progress Software Corp.	305		17,522
Simulations Plus, Inc.	93		4,087
SPS Commerce, Inc. (a)	114		17,362
Veradigm, Inc. (a)	476		6,212
Verra Mobility Corp. (a)	563		9,526
		$	165,436
Telecommunications — 0.94%
A10 Networks, Inc.	104		1,611
ATN International, Inc.	98		4,010
Clearfield, Inc. (a)	84		3,913
Extreme Networks, Inc. (a)	410		7,839
Harmonic, Inc. (a)	418		6,099
InterDigital, Inc.	178		12,976
Lumen Technologies, Inc. (a)	3,203		8,488
NETGEAR, Inc. (a)	75		1,388
Shenandoah Telecommunications Co.	255		4,850
Viavi Solutions, Inc. (a)	233		2,524
		$	53,698
Textiles — 0.18%
UniFirst Corp.	57		10,045
Transportation — 2.18%
ArcBest Corp.	162		14,972
Dorian LPG Ltd.	205		4,088
Forward Air Corp.	188		20,259
Heartland Express, Inc.	958		15,251
Hub Group, Inc., Class A (a)	330		27,700
Marten Transport Ltd.	584		12,235
Matson, Inc.	246		14,679
RXO, Inc. (a)	786		15,437
		$	124,621
Water — 1.13%
American States Water Co.	237		21,067
California Water Service Group	356		20,719
Middlesex Water Co.	90		7,031
SJW Group	203		15,454
		$	64,271
TOTAL COMMON STOCKS		$	5,656,448

See accompanying notes.

81

		Schedule of Investments
	Principal U.S. Small-Cap Adaptive Multi-Factor ETF
		March 31, 2023 (unaudited)
INVESTMENT COMPANIES — 0.34%		Shares Held			Value
Money Market Fund — 0.34%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (b)		19,248		$	19,248
TOTAL INVESTMENT COMPANIES				$	19,248
Total Investments				$	5,675,696
Other Assets and Liabilities — 0.48%					27,603
Total Net Assets — 100.00%				$	5,703,299
(a)	Non-income producing security.
(b)	Current yield shown is as of period end.
	Portfolio Summary
Sector		Percent
Financial		24.13	%
Industrial		18.55	%
Consumer, Cyclical		18.24	%
Consumer, Non-cyclical		17.37	%
Technology		6.64	%
Energy		4.92	%
Basic Materials		4.14	%
Communications		2.73	%
Utilities		2.46	%
Money Market Fund		0.34	%
Other Assets and Liabilities		0.48	%
TOTAL NET ASSETS		100.00	%
See accompanying notes.		82

	Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 99.60%	Shares Held		Value
Aerospace & Defense — 0.49%
AAR Corp. (a)	6,976	$	380,541
Barnes Group, Inc.	5,759		231,972
Moog, Inc., Class A	3,321		334,591
		$	947,104
Agriculture — 0.04%
Turning Point Brands, Inc.	3,417		71,757
Apparel — 1.88%
Crocs, Inc. (a)	17,290		2,186,148
Oxford Industries, Inc.	3,493		368,826
Steven Madden Ltd.	10,852		390,672
Urban Outfitters, Inc. (a)	24,773		686,707
		$	3,632,353
Auto Parts & Equipment — 0.25%
American Axle & Manufacturing Holdings, Inc. (a)	19,282		150,593
Dorman Products, Inc. (a)	1,493		128,786
Methode Electronics, Inc.	3,223		141,425
Standard Motor Products, Inc.	1,545		57,026
		$	477,830
Banks — 9.21%
Amalgamated Financial Corp.	15,910		281,448
Ameris Bancorp	21,809		797,773
Associated Banc-Corp.	60,153		1,081,551
Cadence Bank	50,072		1,039,495
Central Pacific Financial Corp.	10,500		187,950
City Holding Co.	3,776		343,163
Eagle Bancorp, Inc.	11,095		371,350
Enterprise Financial Services Corp.	7,422		330,947
FB Financial Corp.	11,570		359,596
First BanCorp	87,263		996,543
First Bancorp/Southern Pines NC	9,834		349,304
First Bancshares, Inc.	9,587		247,632
First Busey Corp.	10,027		203,949
First Commonwealth Financial Corp.	32,519		404,211
First Financial Bancorp	20,229		440,385
Hanmi Financial Corp.	10,715		198,977
Heartland Financial USA, Inc.	8,040		308,414
Heritage Financial Corp.	12,540		268,356
Hope Bancorp, Inc.	53,856		528,866
Kearny Financial Corp.	22,892		185,883
NBT Bancorp, Inc.	9,491		319,942
Pathward Financial, Inc.	15,065		625,047
Preferred Bank	4,348		238,314
Premier Financial Corp.	7,967		165,156
Renasant Corp.	14,877		454,939
S&T Bancorp, Inc.	8,753		275,282
Sandy Spring Bancorp, Inc.	11,285		293,184
Simmons First National Corp., Class A	37,459		655,158
SouthState Corp.	15,869		1,130,825
Texas Capital Bancshares, Inc. (a)	24,054		1,177,684
Tompkins Financial Corp.	2,883		190,883
TriCo Bancshares	6,208		258,191
Trustmark Corp.	14,462		357,211
United Bankshares, Inc.	35,021		1,232,739
United Community Banks, Inc.	37,441		1,052,841

See accompanying notes.

83

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Banks (continued)
WesBanco, Inc.	12,946	$	397,442
		$	17,750,631
Beverages — 0.22%
MGP Ingredients, Inc.	3,333		322,368
Vita Coco Co., Inc. (a)	4,834		94,843
		$	417,211
Biotechnology — 2.95%
ACADIA Pharmaceuticals, Inc. (a)	30,563		575,196
Adicet Bio, Inc. (a)	6,755		38,909
ADMA Biologics, Inc. (a)	47,619		157,619
Agenus, Inc. (a)	52,186		79,323
Amicus Therapeutics, Inc. (a)	45,014		499,205
AnaptysBio, Inc. (a)	4,069		88,541
Avid Bioservices, Inc. (a)	11,927		223,751
Chinook Therapeutics, Inc. (a)	9,364		216,777
Cytek Biosciences, Inc. (a)	10,985		100,952
Dynavax Technologies Corp. (a)	39,143		383,993
Emergent BioSolutions, Inc. (a)	15,540		160,994
Evolus, Inc. (a)	8,339		70,548
Halozyme Therapeutics, Inc. (a)	19,504		744,858
Innoviva, Inc. (a)	12,136		136,530
Intercept Pharmaceuticals, Inc. (a)	10,527		141,378
iTeos Therapeutics, Inc. (a)	6,861		93,378
Karyopharm Therapeutics, Inc. (a)	26,643		103,641
Ligand Pharmaceuticals, Inc. (a)	2,407		177,059
Liquidia Corp. (a)	7,753		53,573
Organogenesis Holdings, Inc. (a)	23,176		49,365
REGENXBIO, Inc. (a)	8,011		151,488
Rigel Pharmaceuticals, Inc. (a)	55,960		73,867
Syndax Pharmaceuticals, Inc. (a)	12,544		264,929
TransMedics Group, Inc. (a)	6,023		456,122
Vir Biotechnology, Inc. (a)	20,416		475,080
Xencor, Inc. (a)	5,956		166,113
		$	5,683,189
Chemicals — 1.07%
AdvanSix, Inc.	5,150		197,090
American Vanguard Corp.	6,548		143,270
AZZ, Inc.	4,244		175,023
Balchem Corp.	2,851		360,594
Ingevity Corp. (a)	5,625		402,300
Intrepid Potash, Inc. (a)	7,188		198,389
Kronos Worldwide, Inc.	14,728		135,645
Quaker Chemical Corp.	2,322		459,640
		$	2,071,951
Coal — 2.18%
Alpha Metallurgical Resources, Inc.	8,567		1,336,452
Arch Resources, Inc.	9,788		1,286,731
CONSOL Energy, Inc.	10,234		596,335
Ramaco Resources, Inc.	16,950		149,330
SunCoke Energy, Inc.	22,889		205,543
Warrior Met Coal, Inc.	17,240		632,880
		$	4,207,271

See accompanying notes.

84

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Commercial Services — 6.78%
AMN Healthcare Services, Inc. (a)	10,451	$	867,015
ASGN, Inc. (a)	6,083		502,882
Barrett Business Services, Inc.	1,216		107,786
Brink's Co.	6,951		464,327
Carriage Services, Inc.	1,605		48,985
CBIZ, Inc. (a)	6,217		307,679
Chegg, Inc. (a)	17,920		292,096
Cimpress PLC (a)	4,185		183,387
CoreCivic, Inc. (a)	29,597		272,292
CorVel Corp. (a)	883		168,017
CRA International, Inc.	1,087		117,200
Cross Country Healthcare, Inc. (a)	9,541		212,955
Ennis, Inc.	3,881		81,850
EVERTEC, Inc.	8,871		299,396
GEO Group, Inc. (a)	50,081		395,139
Healthcare Services Group, Inc. (a)	18,100		251,047
HealthEquity, Inc. (a)	12,831		753,308
Heidrick & Struggles International, Inc.	3,464		105,167
Herc Holdings, Inc.	5,701		649,344
Huron Consulting Group, Inc. (a)	3,357		269,802
I3 Verticals, Inc., Class A (a)	4,083		100,156
ICF International, Inc.	2,519		276,334
Insperity, Inc.	4,741		576,269
John Wiley & Sons, Inc., Class A	7,650		296,590
Kelly Services, Inc., Class A	5,561		92,257
Kforce, Inc.	3,557		224,945
Korn Ferry	9,796		506,845
Matthews International Corp., Class A	4,202		151,524
Medifast, Inc.	3,402		352,685
Monro, Inc.	3,511		173,549
Multiplan Corp. (a)	53,875		57,108
Payoneer Global, Inc. (a)	71,484		448,920
Perdoceo Education Corp. (a)	6,692		89,874
Progyny, Inc. (a)	4,677		150,225
R1 RCM, Inc. (a)	44,534		668,010
Repay Holdings Corp. (a)	23,865		156,793
Resources Connection, Inc.	7,071		120,631
SP Plus Corp. (a)	2,562		87,851
StoneCo Ltd., Class A (a)	75,696		722,140
Strategic Education, Inc.	1,207		108,425
Stride, Inc. (a)	5,608		220,114
Target Hospitality Corp. (a),(b)	9,395		123,450
TriNet Group, Inc. (a)	5,865		472,778
TrueBlue, Inc. (a)	4,474		79,637
V2X, Inc. (a)	1,420		56,402
WW International, Inc. (a)	11,433		47,104
ZipRecruiter, Inc., Class A (a)	22,688		361,647
		$	13,071,937
Computers — 2.47%
Conduent, Inc. (a)	17,608		60,396
ExlService Holdings, Inc. (a)	5,365		868,218
Insight Enterprises, Inc. (a)	5,873		839,604
Maximus, Inc.	9,810		772,047
Mitek Systems, Inc. (a)	5,630		53,992
NetScout Systems, Inc. (a)	12,419		355,804
Parsons Corp. (a)	9,249		413,800
Qualys, Inc. (a)	9,638		1,253,133

See accompanying notes.

85

Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Computers (continued)
TTEC Holdings, Inc.	4,035	$	150,223
		$	4,767,217
Construction Materials — 1.71%
Apogee Enterprises, Inc.	3,088		133,556
Boise Cascade Co.	8,101		512,388
Gibraltar Industries, Inc. (a)	5,436		263,646
JELD-WEN Holding, Inc. (a)	43,454		550,128
Modine Manufacturing Co. (a)	4,253		98,032
PGT Innovations, Inc. (a)	13,514		339,336
Summit Materials, Inc., Class A (a)	24,306		692,478
UFP Industries, Inc.	8,775		697,349
		$	3,286,913
Distribution/Wholesale — 0.27%
G-III Apparel Group Ltd. (a)	7,226		112,364
MRC Global, Inc. (a)	19,491		189,453
ScanSource, Inc. (a)	2,592		78,901
Titan Machinery, Inc. (a)	4,443		135,289
		$	516,007
Diversified Financial Services — 2.49%
BGC Partners, Inc., Class A	129,680		678,227
Enact Holdings, Inc.	16,050		366,903
Encore Capital Group, Inc. (a)	22,023		1,111,060
Houlihan Lokey, Inc.	16,460		1,440,086
International Money Express, Inc. (a)	8,485		218,743
LendingTree, Inc. (a)	20,309		541,438
StepStone Group, Inc., Class A	18,397		446,495
		$	4,802,952
Electric — 1.37%
ALLETE, Inc.	10,762		692,750
Clearway Energy, Inc., Class A	5,239		157,327
Otter Tail Corp.	5,471		395,389
Portland General Electric Co.	26,297		1,285,660
Unitil Corp.	1,865		106,380
		$	2,637,506
Electrical Components & Equipment — 1.23%
Belden, Inc.	5,330		462,484
Encore Wire Corp.	7,161		1,327,148
Energizer Holdings, Inc.	13,700		475,390
Insteel Industries, Inc.	3,708		103,157
		$	2,368,179
Electronics — 2.53%
Advanced Energy Industries, Inc.	4,522		443,156
Atkore, Inc. (a)	10,881		1,528,563
Badger Meter, Inc.	2,437		296,875
Benchmark Electronics, Inc.	3,091		73,226
CTS Corp.	3,264		161,437
GoPro, Inc., Class A (a)	23,445		117,928
Knowles Corp. (a)	26,269		446,573
Mesa Laboratories, Inc.	1,572		274,675
Napco Security Technologies, Inc. (a)	4,574		171,891
OSI Systems, Inc. (a)	2,561		262,144

See accompanying notes.

86

	Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Electronics (continued)
Sanmina Corp. (a)	7,533	$	459,438
TTM Technologies, Inc. (a)	13,091		176,598
Vishay Intertechnology, Inc.	20,748		469,320
		$	4,881,824
Energy — Alternate Sources — 0.06%
Montauk Renewables, Inc. (a)	7,897		62,149
REX American Resources Corp. (a)	2,062		58,953
		$	121,102
Engineering & Construction — 2.32%
Arcosa, Inc.	5,585		352,469
Comfort Systems USA, Inc.	4,562		665,870
Dycom Industries, Inc. (a)	7,168		671,283
EMCOR Group, Inc.	7,498		1,219,100
Exponent, Inc.	5,547		552,980
Frontdoor, Inc. (a)	13,945		388,787
MYR Group, Inc. (a)	2,411		303,810
NV5 Global, Inc. (a)	1,674		174,046
Sterling Infrastructure, Inc. (a)	3,899		147,694
		$	4,476,039
Entertainment — 0.36%
Accel Entertainment, Inc. (a)	3,689		33,607
Everi Holdings, Inc. (a)	6,942		119,056
Liberty Media Corp.-Liberty Braves, Class C (a)	3,523		118,690
Monarch Casino & Resort, Inc.	628		46,566
RCI Hospitality Holdings, Inc.	778		60,816
Red Rock Resorts, Inc., Class A	6,902		307,622
		$	686,357
Environmental Control — 0.08%
Heritage-Crystal Clean, Inc. (a)	4,614		164,305
Food — 1.72%
Cal-Maine Foods, Inc.	14,828		902,877
Hain Celestial Group, Inc. (a)	29,627		508,103
Ingles Markets, Inc., Class A	1,946		172,610
Simply Good Foods Co. (a)	11,241		447,055
SpartanNash Co.	4,673		115,890
Sprouts Farmers Market, Inc. (a)	31,897		1,117,352
Tootsie Roll Industries, Inc.	1,306		58,654
		$	3,322,541
Forest Products & Paper — 0.28%
Sylvamo Corp.	11,654		539,114
Gas — 1.66%
Brookfield Infrastructure Corp., Class A	10,061		463,410
Northwest Natural Holding Co.	6,983		332,111
ONE Gas, Inc.	8,632		683,913
Southwest Gas Holdings, Inc. (a)	17,568		1,097,122
Spire, Inc.	8,866		621,861
		$	3,198,417
Hand/Machine Tools — 0.30%
Kennametal, Inc.	20,808		573,885

See accompanying notes.

87

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Healthcare — Products — 5.57%
Artivion, Inc. (a)	6,873	$	90,036
Atrion Corp.	82		51,489
Avanos Medical, Inc. (a)	5,432		161,548
CONMED Corp.	7,109		738,341
Embecta Corp.	8,206		230,753
Glaukos Corp. (a)	7,884		394,988
Haemonetics Corp. (a)	7,299		603,992
Inogen, Inc. (a)	4,357		54,375
Integer Holdings Corp. (a)	4,089		316,898
Lantheus Holdings, Inc. (a)	18,472		1,525,048
LeMaitre Vascular, Inc.	1,856		95,528
LivaNova PLC (a)	8,955		390,259
Merit Medical Systems, Inc. (a)	5,991		443,034
Neogen Corp. (a)	121,775		2,255,273
NuVasive, Inc. (a)	14,370		593,625
OmniAb, Inc., Earnout Shares (a)	1,130		—
OmniAb, Inc., Earnout Shares (a)	1,130		—
Omnicell, Inc. (a)	9,197		539,588
Orthofix Medical, Inc. (a)	4,473		74,923
Shockwave Medical, Inc. (a)	4,832		1,047,723
Silk Road Medical, Inc. (a)	6,299		246,480
STAAR Surgical Co. (a)	8,795		562,440
UFP Technologies, Inc. (a)	813		105,560
Varex Imaging Corp. (a)	4,795		87,221
ViewRay, Inc. (a)	15,872		54,917
Zimvie, Inc. (a)	9,926		71,765
		$	10,735,804
Healthcare — Services — 1.71%
Addus HomeCare Corp. (a)	1,379		147,222
Agiliti, Inc. (a)	3,923		62,689
Cano Health, Inc. (a),(b)	30,663		27,903
DocGo, Inc. (a)	13,097		113,289
Ensign Group, Inc.	4,846		462,987
Fulgent Genetics, Inc. (a)	6,359		198,528
Joint Corp. (a)	3,361		56,566
Medpace Holdings, Inc. (a)	6,472		1,217,060
ModivCare, Inc. (a)	1,789		150,419
OPKO Health, Inc. (a)	65,960		96,302
Pediatrix Medical Group, Inc. (a)	10,710		159,686
RadNet, Inc. (a)	4,806		120,294
Select Medical Holdings Corp.	12,346		319,144
U.S. Physical Therapy, Inc.	1,655		162,041
		$	3,294,130
Home Builders — 2.36%
Beazer Homes USA, Inc. (a)	6,595		104,729
Cavco Industries, Inc. (a)	919		292,003
Century Communities, Inc.	3,417		218,415
Installed Building Products, Inc.	2,137		243,682
KB Home	22,814		916,666
LGI Homes, Inc. (a)	3,187		363,414
Meritage Homes Corp.	4,771		557,062
Skyline Champion Corp. (a)	5,280		397,214
Taylor Morrison Home Corp. (a)	15,918		609,023
Tri Pointe Homes, Inc. (a)	15,908		402,791

See accompanying notes.

88

Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Home Builders (continued)
Winnebago Industries, Inc.	7,835	$	452,079
		$	4,557,078
Home Furnishings — 0.14%
Ethan Allen Interiors, Inc.	3,114		85,510
Sleep Number Corp. (a)	6,078		184,832
		$	270,342
Household Products — 0.72%
Edgewell Personal Care Co.	8,930		378,811
elf Beauty, Inc. (a)	12,176		1,002,693
		$	1,381,504
Household Products/Wares — 0.35%
ACCO Brands Corp.	27,220		144,810
Central Garden & Pet Co., Class A (a)	3,033		118,499
Helen of Troy Ltd. (a)	4,281		407,423
		$	670,732
Insurance — 2.80%
American Equity Investment Life Holding Co.	30,090		1,097,984
Essent Group Ltd.	36,636		1,467,271
Jackson Financial, Inc., Class A	40,024		1,497,298
NMI Holdings, Inc., Class A (a)	31,230		697,366
Palomar Holdings, Inc. (a)	11,549		637,505
		$	5,397,424
Internet — 2.67%
1-800-Flowers.com, Inc., Class A (a)	11,828		136,022
Cargurus, Inc. (a)	43,075		804,641
Cars.com, Inc. (a)	12,275		236,908
ePlus, Inc. (a)	2,458		120,540
Figs, Inc., Class A (a)	58,554		362,449
Perficient, Inc. (a)	7,402		534,351
Q2 Holdings, Inc. (a)	13,618		335,275
QuinStreet, Inc. (a)	6,859		108,852
Revolve Group, Inc. (a)	18,521		487,102
Shutterstock, Inc.	10,397		754,822
Yelp, Inc. (a)	18,622		571,696
Ziff Davis, Inc. (a)	8,780		685,279
		$	5,137,937
Leisure Time — 0.23%
Camping World Holdings, Inc., Class A	12,609		263,150
Malibu Boats, Inc., Class A (a)	2,388		134,803
MasterCraft Boat Holdings, Inc. (a)	1,691		51,457
		$	449,410
Machinery — Construction & Mining — 0.37%
Terex Corp.	14,612		706,929
Machinery — Diversified — 0.84%
Albany International Corp., Class A	3,064		273,799
Applied Industrial Technologies, Inc.	4,020		571,363
GrafTech International Ltd.	71,806		348,977
Kadant, Inc.	1,455		303,397

See accompanying notes.

89

	Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Machinery — Diversified (continued)
Tennant Co.	1,655	$	113,417
		$	1,610,953
Media — 0.65%
AMC Networks, Inc., Class A (a)	12,614		221,754
Gannett Co., Inc. (a)	32,552		60,872
Liberty Latin America Ltd., Class C (a)	38,828		320,719
Scholastic Corp.	8,230		281,631
Sinclair Broadcast Group, Inc., Class A	21,164		363,174
		$	1,248,150
Metal Fabrication & Hardware — 0.75%
Mueller Industries, Inc.	8,478		622,963
Proto Labs, Inc. (a)	5,325		176,524
Ryerson Holding Corp.	6,376		231,959
Standex International Corp.	1,287		157,580
TimkenSteel Corp. (a)	13,522		247,994
		$	1,437,020
Mining — 0.34%
Constellium SE (a)	22,876		349,546
Kaiser Aluminum Corp.	4,129		308,147
		$	657,693
Miscellaneous Manufacturers — 0.80%
EnPro Industries, Inc.	2,026		210,481
Fabrinet (a)	4,167		494,873
Hillenbrand, Inc.	8,831		419,737
LSB Industries, Inc. (a)	16,797		173,513
Smith & Wesson Brands, Inc.	10,426		128,344
Sturm Ruger & Co., Inc.	1,938		111,319
		$	1,538,267
Office & Business Equipment — 0.28%
Xerox Holdings Corp.	34,711		534,549
Office Furnishings — 0.04%
Interface, Inc.	8,761		71,139
Oil & Gas — 4.40%
Berry Corp.	9,125		71,631
California Resources Corp.	11,461		441,249
Callon Petroleum Co. (a)	19,570		654,421
Chord Energy Corp.	6,120		823,752
Comstock Resources, Inc.	53,449		576,715
CVR Energy, Inc.	10,827		354,909
Denbury, Inc. (a)	10,369		908,635
HighPeak Energy, Inc.	1,910		43,930
Magnolia Oil & Gas Corp., Class A	22,403		490,178
Matador Resources Co.	16,568		789,465
Par Pacific Holdings, Inc. (a)	10,354		302,337
PBF Energy, Inc., Class A	31,004		1,344,333
Permian Resources Corp.	94,196		989,058
Ranger Oil Corp., Class A	5,009		204,568
Ring Energy, Inc. (a),(b)	27,417		52,092
SandRidge Energy, Inc. (a)	11,808		170,153
Sitio Royalties Corp., Class A	4,855		109,723

See accompanying notes.

90

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Oil & Gas (continued)
Talos Energy, Inc. (a)	10,856	$	161,103
		$	8,488,252
Oil & Gas Services — 0.49%
ChampionX Corp.	27,308		740,866
NOW, Inc. (a)	18,705		208,561
		$	949,427
Packaging & Containers — 0.64%
Greif, Inc., Class A	8,100		513,297
O-I Glass, Inc. (a)	28,212		640,695
TriMas Corp.	3,205		89,291
		$	1,243,283
Pharmaceuticals — 3.41%
AbCellera Biologics, Inc. (a)	24,701		186,246
Alector, Inc. (a)	9,166		56,738
Alkermes PLC (a)	29,753		838,737
Amneal Pharmaceuticals, Inc. (a)	23,368		32,482
Amphastar Pharmaceuticals, Inc. (a)	5,088		190,800
BellRing Brands, Inc. (a)	18,111		615,774
Catalyst Pharmaceuticals, Inc. (a)	35,162		582,986
Collegium Pharmaceutical, Inc. (a)	4,760		114,192
Corcept Therapeutics, Inc. (a)	9,126		197,669
Eagle Pharmaceuticals, Inc. (a)	3,434		97,423
Harmony Biosciences Holdings, Inc. (a)	8,028		262,114
Herbalife Nutrition Ltd. (a)	22,319		359,336
Ironwood Pharmaceuticals, Inc. (a)	42,507		447,174
Option Care Health, Inc. (a)	17,625		559,946
Pacira BioSciences, Inc. (a)	7,693		313,951
PetIQ, Inc. (a)	10,289		117,706
Phibro Animal Health Corp., Class A	4,186		64,129
Prestige Consumer Healthcare, Inc. (a)	5,371		336,386
Revance Therapeutics, Inc. (a)	11,701		376,889
Senseonics Holdings, Inc. (a),(b)	39,310		27,910
Seres Therapeutics, Inc. (a)	10,651		60,391
SIGA Technologies, Inc.	50,035		287,701
Supernus Pharmaceuticals, Inc. (a)	8,404		304,477
USANA Health Sciences, Inc. (a)	1,233		77,556
Vanda Pharmaceuticals, Inc. (a)	8,318		56,479
		$	6,565,192
Pipelines — 0.06%
Kinetik Holdings, Inc.	3,774		118,126
Real Estate — 0.84%
Alexander & Baldwin, Inc. (a)	11,141		210,676
Anywhere Real Estate, Inc. (a)	70,714		373,370
Cushman & Wakefield PLC (a)	46,725		492,482
Marcus & Millichap, Inc.	6,716		215,651
McGrath RentCorp	1,897		177,009
RE/MAX Holdings, Inc., Class A	7,575		142,107
		$	1,611,295
REITs — 5.10%
American Assets Trust, Inc.	11,882		220,886
Broadstone Net Lease, Inc.	51,310		872,783
CareTrust REIT, Inc.	29,774		582,975

See accompanying notes.

91

	Schedule of Investments
Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
REITs (continued)
City Office REIT, Inc.	15,277	$	105,411
Corporate Office Properties Trust	27,302		647,330
Empire State Realty Trust, Inc., Class A	50,042		324,773
Essential Properties Realty Trust, Inc.	41,599		1,033,735
Four Corners Property Trust, Inc.	18,412		494,546
Franklin Street Properties Corp.	41,236		64,741
Getty Realty Corp.	9,966		359,075
Industrial Logistics Properties Trust	54,072		166,001
Innovative Industrial Properties, Inc.	11,903		904,509
LTC Properties, Inc.	11,368		399,358
Necessity Retail REIT, Inc.	27,974		175,677
Office Properties Income Trust	14,597		179,543
Paramount Group, Inc.	59,421		270,960
Piedmont Office Realty Trust, Inc., Class A	49,659		362,511
PotlatchDeltic Corp.	22,293		1,103,503
Sabra Health Care REIT, Inc.	91,275		1,049,663
Uniti Group, Inc.	79,076		280,720
Universal Health Realty Income Trust	2,145		103,196
Whitestone REIT	12,787		117,640
		$	9,819,536
Retail — 6.35%
Academy Sports & Outdoors, Inc.	20,917		1,364,834
Arko Corp.	4,292		36,439
Asbury Automotive Group, Inc. (a)	2,509		526,890
Bloomin' Brands, Inc.	17,848		457,801
BlueLinx Holdings, Inc. (a)	3,840		260,966
Boot Barn Holdings, Inc. (a)	9,139		700,413
Caleres, Inc.	7,225		156,277
Children's Place, Inc. (a)	4,437		178,589
Chuy's Holdings, Inc. (a)	1,388		49,760
Conn's, Inc. (a)	3,029		18,356
Container Store Group, Inc. (a)	6,386		21,904
Denny's Corp. (a)	6,856		76,513
Designer Brands, Inc., Class A	16,242		141,955
Dillard's, Inc., Class A	2,121		652,589
Foot Locker, Inc.	34,512		1,369,781
Genesco, Inc. (a)	2,354		86,816
GMS, Inc. (a)	6,817		394,636
Group 1 Automotive, Inc.	2,649		599,787
Haverty Furniture Cos., Inc.	2,172		69,309
Hibbett, Inc.	4,119		242,939
Jack in the Box, Inc.	4,999		437,862
La-Z-Boy, Inc.	5,003		145,487
MarineMax, Inc. (a)	4,647		133,601
Movado Group, Inc.	2,037		58,605
Murphy USA, Inc.	4,148		1,070,391
National Vision Holdings, Inc. (a)	10,279		193,656
Nu Skin Enterprises, Inc., Class A	8,672		340,896
OneWater Marine, Inc., Class A (a)	1,159		32,417
Patrick Industries, Inc.	2,854		196,384
PriceSmart, Inc.	2,104		150,394
Qurate Retail, Inc., Series A (a)	45,150		44,599
Rite Aid Corp. (a),(b)	22,517		50,438
Rush Enterprises, Inc., Class A	6,260		341,796
Ruth's Hospitality Group, Inc.	4,621		75,877
Sally Beauty Holdings, Inc. (a)	20,888		325,435
Shoe Carnival, Inc.	4,548		116,656

See accompanying notes.

92

	Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Retail (continued)
Texas Roadhouse, Inc.	9,393	$	1,015,008
Zumiez, Inc. (a)	5,133		94,653
		$	12,230,709
Savings & Loans — 0.47%
OceanFirst Financial Corp.	16,519		305,271
Washington Federal, Inc.	20,276		610,713
		$	915,984
Semiconductors — 4.29%
Alpha & Omega Semiconductor Ltd. (a)	7,649		206,141
Amkor Technology, Inc.	17,316		450,562
Axcelis Technologies, Inc. (a)	9,869		1,315,044
Diodes, Inc. (a)	4,991		462,965
FormFactor, Inc. (a)	12,035		383,315
Kulicke & Soffa Industries, Inc.	15,806		832,818
MaxLinear, Inc. (a)	15,587		548,818
Onto Innovation, Inc. (a)	6,659		585,193
Photronics, Inc. (a)	19,062		316,048
Power Integrations, Inc.	10,942		926,131
Rambus, Inc. (a)	14,834		760,391
Semtech Corp. (a)	27,124		654,774
SiTime Corp. (a)	4,627		658,098
Veeco Instruments, Inc. (a)	7,686		162,405
		$	8,262,703
Software — 3.84%
8x8, Inc. (a)	25,503		106,347
ACI Worldwide, Inc. (a)	18,464		498,159
Adeia, Inc.	16,896		149,699
Apollo Medical Holdings, Inc. (a)	6,618		241,358
Box, Inc., Class A (a)	28,284		757,728
Cerence, Inc. (a)	12,847		360,872
CommVault Systems, Inc. (a)	5,803		329,262
CSG Systems International, Inc.	3,634		195,146
Digi International, Inc. (a)	7,724		260,144
Ebix, Inc.	5,593		73,772
Envestnet, Inc. (a)	7,958		466,896
Everbridge, Inc. (a)	8,880		307,870
Evolent Health, Inc., Class A (a)	25,288		820,596
Health Catalyst, Inc. (a)	11,179		130,459
NextGen Healthcare, Inc. (a)	5,133		89,365
Privia Health Group, Inc. (a)	19,534		539,334
Progress Software Corp.	6,186		355,386
PubMatic, Inc., Class A (a)	14,205		196,313
Sapiens International Corp. NV	4,073		88,466
Simulations Plus, Inc.	2,748		120,747
SPS Commerce, Inc. (a)	3,244		494,061
Upland Software, Inc. (a)	12,794		55,014
Veradigm, Inc. (a)	26,878		350,758
Verra Mobility Corp. (a)	23,834		403,271
		$	7,391,023
Telecommunications — 0.82%
A10 Networks, Inc.	12,087		187,228
Clearfield, Inc. (a)	5,739		267,323
EchoStar Corp., Class A (a)	6,278		114,825
Extreme Networks, Inc. (a)	21,922		419,149

See accompanying notes.

93

		Schedule of Investments
	Principal U.S. Small-Cap Multi-Factor ETF
		March 31, 2023 (unaudited)
COMMON STOCKS (continued)			Shares Held		Value
Telecommunications (continued)
InterDigital, Inc.			6,264	$	456,645
NETGEAR, Inc. (a)			3,965		73,392
U.S. Cellular Corp. (a)			3,372		69,901
				$	1,588,463
Textiles — 0.16%
UniFirst Corp.			1,758		309,812
Toys, Games & Hobbies — 0.04%
Funko, Inc., Class A (a)			7,636		72,007
Transportation — 4.15%
Air Transport Services Group, Inc. (a)			9,452		196,885
ArcBest Corp.			6,417		593,059
Covenant Logistics Group, Inc.			3,364		119,153
Eagle Bulk Shipping, Inc.			9,733		442,851
FLEX LNG Ltd. (a)			9,002		302,287
Forward Air Corp.			4,709		507,442
Genco Shipping & Trading Ltd.			35,661		558,451
Golden Ocean Group Ltd. (a)			102,485		975,657
Heartland Express, Inc.			8,777		139,730
Hub Group, Inc., Class A (a)			7,531		632,152
International Seaways, Inc.			8,666		361,199
Marten Transport Ltd.			13,713		287,287
Matson, Inc.			11,353		677,434
Safe Bulkers, Inc.			36,281		133,877
Saia, Inc. (a)			7,102		1,932,312
SFL Corp. Ltd.			13,863		131,699
				$	7,991,475
TOTAL COMMON STOCKS				$	191,929,940
INVESTMENT COMPANIES — 0.43%			Shares Held		Value
Money Market Funds — 0.43%
Principal Government Money Market Fund — Class R-6 4.72% (c),(d),(e)			233,283	$	233,283
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (e)			599,346		599,346
TOTAL INVESTMENT COMPANIES				$	832,629
Total Investments				$	192,762,569
Other Assets and Liabilities — (0.03)%					(66,190	)
Total Net Assets — 100.00%				$	192,696,379
(a)	Non-income producing security.
(b)	Security or a portion of the security was on loan. At the end of the period, the value of these securities totaled $200,020 or
	0.10% of net assets.
(c)	Affiliated Security. Security is either an affiliate (and registered under the Investment Company Act of 1940) or an affiliate
	as defined by the Investment Company Act of 1940 (controls 5.00% or more of the outstanding voting shares of the security).
	Please see Affiliated Securities sub-schedule for transactional information.
(d)	Security or a portion of the security was received as collateral for securities lending. At the end of the period, the value of
	these securities totaled $233,283 or 0.12% of net assets.
(e)	Current yield shown is as of period end.
See accompanying notes.		94

			Schedule of Investments
		Principal U.S. Small-Cap Multi-Factor ETF
			March 31, 2023 (unaudited)
Portfolio Summary
Sector					Percent
Consumer, Non-cyclical						23.46	%
Financial						20.91	%
Industrial						16.20	%
Consumer, Cyclical						12.08	%
Technology						10.87	%
Energy						7.21	%
Communications						4.14	%
Utilities						3.03	%
Basic Materials						1.70	%
Money Market Funds						0.43	%
Other Assets and Liabilities						(0.03	)%
TOTAL NET ASSETS						100.00	%
			June 30, 2022		Purchases					Sales		March 31, 2023
Affiliated Securities			Value			Cost				Proceeds		Value
Principal Government Money
Market Fund — Class R-6 4.72%		$	—		$	5,813,397			$	5,580,114	$	233,283
Principal Government Money
Market Fund — Institutional Class
4.67	%		5,359,834			17,843,390				23,203,224		—
		$	5,359,834	$	23,656,787			$	28,783,338		$	233,283
									Realized Gain
						Realized				from		Change in
					Gain/(Loss) on				Capital Gain			Unrealized
			Income (a)		Investments				Distributions			Gain/(Loss)
Principal Government Money
Market Fund — Class R-6 4.72%		$	—		$	—			$	—	$	—
Principal Government Money
Market Fund — Institutional Class
4.67	%		—			—				—		—
		$	—		$	—			$	—	$	—
(a) Amount excludes earnings from securities lending collateral.

See accompanying notes.

95

	Schedule of Investments
	Principal Value ETF
	March 31, 2023 (unaudited)
COMMON STOCKS — 99.41%		Shares Held		Value
Advertising — 1.47%
Omnicom Group, Inc.		5,037	$	475,190
Aerospace & Defense — 2.65%
Northrop Grumman Corp.		824		380,457
Raytheon Technologies Corp.		4,875		477,409
			$	857,866
Agriculture — 3.65%
Altria Group, Inc.		8,496		379,092
Archer-Daniels-Midland Co.		4,456		354,965
Philip Morris International, Inc.		4,597		447,058
			$	1,181,115
Auto Parts & Equipment — 1.41%
BorgWarner, Inc.		9,292		456,330
Banks — 6.00%
Bank of America Corp.		16,432		469,955
M&T Bank Corp.		2,058		246,075
Northern Trust Corp.		3,498		308,279
PNC Financial Services Group, Inc.		2,376		301,990
Wells Fargo & Co.		11,688		436,897
Zions Bancorp NA		5,992		179,341
			$	1,942,537
Beverages — 3.74%
Coca-Cola Co.		8,892		551,571
Constellation Brands, Inc., Class A		1,498		338,383
Molson Coors Beverage Co., Class B		6,200		320,416
			$	1,210,370
Biotechnology — 2.56%
Amgen, Inc.		1,833		443,128
Corteva, Inc.		6,388		385,260
			$	828,388
Chemicals — 2.91%
CF Industries Holdings, Inc.		3,720		269,663
Eastman Chemical Co.		3,608		304,299
FMC Corp.		3,033		370,420
			$	944,382
Computers — 7.87%
Accenture PLC, Class A		1,719		491,307
Apple, Inc.		8,132		1,340,967
International Business Machines Corp.		3,112		407,952
Leidos Holdings, Inc.		3,358		309,138
			$	2,549,364
Construction Materials — 1.33%
Johnson Controls International PLC		7,146		430,332
Diversified Financial Services — 4.54%
American Express Co.		2,720		448,664
Franklin Resources, Inc.		13,369		360,161
Invesco Ltd.		19,350		317,340
Raymond James Financial, Inc.		3,677		342,954
			$	1,469,119

See accompanying notes.

96

Schedule of Investments
Principal Value ETF
March 31, 2023 (unaudited)
COMMON STOCKS (continued)	Shares Held		Value
Electronics — 1.40%
Honeywell International, Inc.	2,369	$	452,763
Food — 6.11%
Conagra Brands, Inc.	10,234		384,389
General Mills, Inc.	5,160		440,974
Hershey Co.	1,625		413,416
J M Smucker Co.	2,584		406,644
Sysco Corp.	4,328		334,251
		$	1,979,674
Household Products/Wares — 1.26%
Clorox Co.	2,590		409,842
Insurance — 4.32%
Arthur J Gallagher & Co.	2,239		428,343
Assurant, Inc.	1,847		221,769
Cincinnati Financial Corp.	2,810		314,945
Marsh & McLennan Cos., Inc.	2,600		433,030
		$	1,398,087
Machinery — Construction & Mining — 1.48%
Caterpillar, Inc.	2,103		481,250
Machinery — Diversified — 4.10%
Deere & Co.	1,210		499,585
Dover Corp.	2,740		416,315
Otis Worldwide Corp.	4,872		411,197
		$	1,327,097
Media — 1.02%
Fox Corp., Class A	9,752		332,056
Oil & Gas — 4.49%
Chevron Corp.	3,917		639,098
Hess Corp.	3,236		428,252
Phillips 66	3,823		387,576
		$	1,454,926
Oil & Gas Services — 1.47%
Schlumberger Ltd.	9,688		475,681
Packaging & Containers — 2.72%
Amcor PLC	27,257		310,185
Packaging Corp. of America	2,276		315,977
Sealed Air Corp.	5,576		255,994
		$	882,156
Pharmaceuticals — 8.53%
AmerisourceBergen Corp.	2,297		367,773
Becton Dickinson & Co.	1,560		386,162
Cardinal Health, Inc.	6,285		474,518
CVS Health Corp.	4,730		351,486
Johnson & Johnson	4,345		673,475
Organon & Co.	9,367		220,312
Viatris, Inc.	30,041		288,994
		$	2,762,720
Pipelines — 1.06%
Williams Cos., Inc.	11,486		342,972

See accompanying notes.

97

	Schedule of Investments
	Principal Value ETF
	March 31, 2023 (unaudited)
COMMON STOCKS (continued)		Shares Held		Value
REITs — 8.20%
Essex Property Trust, Inc.		1,242	$	259,752
Kimco Realty Corp.		16,786		327,830
Public Storage		1,172		354,108
Realty Income Corp.		5,209		329,834
Regency Centers Corp.		5,398		330,250
Simon Property Group, Inc.		3,506		392,567
Ventas, Inc.		6,648		288,191
VICI Properties, Inc.		11,404		371,998
			$	2,654,530
Retail — 5.40%
Genuine Parts Co.		2,519		421,454
McDonald's Corp.		2,025		566,210
Ross Stores, Inc.		4,425		469,625
Walgreens Boots Alliance, Inc.		8,392		290,196
			$	1,747,485
Semiconductors — 1.68%
Texas Instruments, Inc.		2,923		543,707
Shipbuilding — 0.99%
Huntington Ingalls Industries, Inc.		1,545		319,846
Software — 4.07%
Jack Henry & Associates, Inc.		1,832		276,119
Microsoft Corp.		3,610		1,040,763
			$	1,316,882
Telecommunications — 2.33%
Corning, Inc.		10,302		363,455
Juniper Networks, Inc.		11,408		392,663
			$	756,118
Toys, Games & Hobbies — 0.65%
Hasbro, Inc.		3,911		209,981
TOTAL COMMON STOCKS			$	32,192,766
INVESTMENT COMPANIES — 0.39%		Shares Held		Value
Money Market Fund — 0.39%
State Street Institutional U.S. Government Money Market Fund — Institutional
Class 1.49% (a)		125,551	$	125,551
TOTAL INVESTMENT COMPANIES			$	125,551
Total Investments			$	32,318,317
Other Assets and Liabilities — 0.20%				63,218
Total Net Assets — 100.00%			$	32,381,535
(a) Current yield shown is as of period end.
See accompanying notes.	98

		Schedule of Investments
		Principal Value ETF
		March 31, 2023 (unaudited)
	Portfolio Summary
Sector		Percent
Consumer, Non-cyclical		25.85	%
Financial		23.05	%
Industrial		14.67	%
Technology		13.62	%
Consumer, Cyclical		7.45	%
Energy		7.02	%
Communications		4.83	%
Basic Materials		2.92	%
Money Market Fund		0.39	%
Other Assets and Liabilities		0.20	%
TOTAL NET ASSETS		100.00	%

See accompanying notes.

99

Principal Exchange-Traded Funds
March 31, 2023 (unaudited)

1. Security Valuation

The Funds may invest in series of Principal Funds, Inc. and other investment funds, which may include money market funds and other registered open-end investment companies. Investments in registered open-end investment companies are valued at the respective fund’s closing net asset value (“NAV”) per share on the day of valuation.

The Funds value securities for which market quotations are readily available at fair value, which is determined using the last reported sale price. If no sales are reported, as is regularly the case for some securities traded over-the-counter (“OTC”), securities are valued using the last reported bid price or an evaluated bid price provided by a pricing service.

Pricing services use modeling techniques that incorporate security characteristics such as current quotations by broker/dealers, coupon, maturity, quality, type of issue, trading characteristics, other yield and risk factors and other market conditions to determine an evaluated bid price. When reliable market quotations are not considered to be readily available, which may be the case, for example, with respect to restricted securities, certain debt securities, preferred stocks, and foreign securities, the investments are valued at their fair value as determined in good faith by the Principal Global Investors, LLC (“the Advisor”) under procedures established and periodically reviewed by the Board of Trustees.

The value of foreign securities used in computing the NAV per share is generally determined as of the close of the foreign exchange where the security is principally traded. Events that occur after the close of the applicable foreign market or exchange but prior to the calculation of the Fund’s NAV are reflected in the Fund’s NAV and these securities are valued at fair value. Many factors, provided by independent pricing services, are reviewed in the course of making a good faith determination of a security’s fair value including, but not limited to, price movements in American Depository Receipts (“ADRs”), futures contracts, industry indices, general indices, and foreign currencies.

To the extent the Funds invest in foreign securities listed on foreign exchanges which trade on days on which the Funds do not determine NAV, for example, weekends and other customary national U.S. holidays, the Fund’s NAV could be significantly affected on days when shares are not able to be issued or redeemed by Authorized Participants (“APs”).

Certain securities issued by companies in emerging market countries may have more than one quoted valuation at any given point in time, sometimes referred to as a “local” price and a “premium” price. The premium price is often a negotiated price, which may not consistently represent a price at which a specific transaction can be effected. It is the policy of the Funds to value such securities at prices at which it is expected those shares may be sold, and the Advisor, or any sub-advisor, is authorized to make such determinations subject to such oversight by the Board of Trustees, as may occasionally be necessary.

2. Fair Valuation

Fair value is defined as the price that the Funds would receive upon selling a security or transferring a liability in a timely transaction to an independent buyer in the principal or most advantageous market of the security at the measurement date. In determining fair value, the Funds may use one or more of the following approaches: market, income and/or cost. A hierarchy for inputs is used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available.

Observable inputs are inputs that reflect the assumptions market participants would use in pricing the asset or liability developed based on market data obtained from sources independent of the Funds. Unobservable inputs are inputs that reflect the Fund’s own estimates about the estimates market participants would use in pricing the asset or liability developed based on the best information available in the circumstances.

The three-tier hierarchy of inputs is summarized in the three broad levels listed below.

Level 1 — Quoted prices are available in active markets for identical securities as of the reporting date. Investments which are generally included in this category include listed equities and listed derivatives.

Level 2 — Other significant observable inputs (including quoted prices for similar investments, interest rates, prepayment speeds, credit risk, etc.). Investments which are generally included in this category include certain corporate bonds, senior floating rate interests, OTC derivatives, mortgage-backed securities and municipal bonds.

100

Principal Exchange-Traded Funds
March 31, 2023 (unaudited) (continued)

2. Fair Valuation (continued)

Level 3 — Significant unobservable inputs (including the Funds’ assumptions in determining the fair value of investments). Investments which are generally included in this category include certain corporate bonds and certain common stocks.

The availability of observable inputs can vary from security to security and is affected by a wide variety of factors, including, for example, the type of security, whether the security is new and not yet established in the market place, and other characteristics particular to the transaction. To the extent that valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Funds in determining fair value is greatest for instruments categorized in Level 3.

In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, for disclosure purposes, the level in the fair value hierarchy within which the fair value measurement in its entirety falls is determined based on the lowest level input that is significant to the fair value measurement in its entirety.

Fair value is a market based measure considered from the perspective of a market participant who holds the asset rather than an entity specific measure. Therefore, even when market assumptions are not readily available, the Funds’ own assumptions are set to reflect those that market participants would use in pricing the asset or liability at the measurement date. The Funds use prices and inputs that are current as of the measurement date, to the extent available.

Investments which are included in the Level 3 category may be valued using quoted prices from brokers and dealers participating in the market for these investments. These investments are classified as Level 3 investments due to the lack of market transparency and market corroboration to support these quoted prices.

Valuation models may be used as the pricing source for other investments classified as Level 3. Valuation models rely on one or more significant unobservable inputs such as prepayment rates, probability of default, or loss severity in the event of default. Significant increases in any of those inputs in isolation would result in a significantly lower fair value measurement.

The fair values of these entities are dependent on economic, political and other considerations. The values of the underlying investee entities may be affected by significant changes in the economic conditions, changes in government policies, and other factors (e.g., natural disasters, pandemics, accidents, conflicts, etc.).

The inputs or methodology used for valuing securities are not necessarily an indication of the risk associated with investing in those instruments.

During the period there were no significant purchases, sales, or transfers into or out of Level 3.

The following is a summary of the inputs used as of March 31, 2023, in valuing the Funds' securities carried at fair value:

				Level 2 —
				Other		Level 3 —
		Level 1 —		Significant		Significant
		Quoted		Observable		Unobservable
Fund		Prices		Inputs		Inputs		Totals (Level 1,2,3)
Principal Active High Yield ETF
Bonds*	$	— $		71,461,660	$		— $	71,461,660
Senior Floating Rate Interests*		—		6,072,040			—	6,072,040
Investment Companies		4,726,332		—			—	4,726,332
Total investments in securities	$	4,726,332	$	77,533,700	$		— $	82,260,032

101

Principal Exchange-Traded Funds
March 31, 2023 (unaudited) (continued)
2. Fair Valuation (continued)
						Level 2 —
						Other		Level 3 —
		Level 1 —				Significant		Significant
		Quoted				Observable		Unobservable
Fund		Prices				Inputs		Inputs		Totals (Level 1,2,3)
Principal Healthcare Innovators ETF
Common Stocks*	$	51,474,653		$		— $			— $	51,474,653
Investment Companies		755,338				—			—	755,338
Total investments in securities	$	52,229,991		$		— $			— $	52,229,991
Principal International Adaptive Multi-Factor ETF
Common Stocks*
Basic Materials	$	1,024,590		$		— $			— $	1,024,590
Communications		943,155				—			—	943,155
Consumer, Cyclical		2,138,098				—			—	2,138,098
Consumer, Non-cyclical		3,445,365				—			—	3,445,365
Diversified		33,966				—			—	33,966
Energy		958,971				1,703			—	960,674
Financial		2,955,254				—			—	2,955,254
Industrial		1,986,992				—			—	1,986,992
Technology		933,893				—			—	933,893
Utilities		531,091				—			—	531,091
Preferred Stocks*		68,637				—			—	68,637
Investment Companies		64,624				—			—	64,624
Total investments in securities	$	15,084,636		$		1,703	$		— $	15,086,339
Principal Investment Grade Corporate Active ETF
Bonds*	$	—		$		36,668,702	$		— $	36,668,702
U.S. Government & Government Agency
Obligations*		—				1,167,945			—	1,167,945
Investment Companies		2,625,349				—			—	2,625,349
Total investments in securities	$	2,625,349		$		37,836,647	$		— $	40,461,996
Derivative Assets
Interest rate contracts
Futures	$	122,543		$		— $			— $	122,543
Derivative Liabilities
Interest rate contracts
Futures	$	(18,881	)	$		— $			— $	(18,881	)
Principal Millennial Global Growth ETF
Common Stocks*	$	29,774,747			$	— $			— $	29,774,747
Investment Companies		699,345				—			—	699,345
Total investments in securities	$	30,474,092			$	— $			— $	30,474,092
Principal Quality ETF
Common Stocks*	$	28,853,594			$	— $			— $	28,853,594
Investment Companies		52,798				—			—	52,798
Total investments in securities	$	28,906,392			$	— $			— $	28,906,392
Principal Real Estate Active Opportunities ETF
Common Stocks*	$	4,997,999			$	— $			— $	4,997,999
Investment Companies		49,923				—			—	49,923
Total investments in securities	$	5,047,922			$	— $			— $	5,047,922
Principal Spectrum Preferred Securities Active ETF
Bonds*	$	— $				488,871,095	$		— $	488,871,095
Investment Companies		33,738,748				—			—	33,738,748
Total investments in securities	$	33,738,748			$	488,871,095	$		— $	522,609,843
Principal Spectrum Tax-Advantaged Dividend Active ETF
Preferred Stocks*	$	2,451,780			$	— $			— $	2,451,780
Bonds*		—				16,934,970			—	16,934,970
Investment Companies		413,785				—			—	413,785
Total investments in securities	$	2,865,565			$	16,934,970	$		— $	19,800,535
Principal U.S. Large-Cap Adaptive Multi-Factor ETF
Common Stocks*	$	6,025,190			$	— $			— $	6,025,190
Investment Companies		20,769				—			—	20,769
Total investments in securities	$	6,045,959			$	— $			— $	6,045,959

102

Principal Exchange-Traded Funds
March 31, 2023 (unaudited) (continued)
2. Fair Valuation (continued)
				Level 2 —
				Other	Level 3 —
		Level 1 —		Significant	Significant
		Quoted		Observable	Unobservable
Fund		Prices		Inputs	Inputs		Totals (Level 1,2,3)
Principal U.S. Mega-Cap ETF
Common Stocks*	$	1,161,256,240	$	— $		— $	1,161,256,240
Investment Companies		4,073,542		—		—	4,073,542
Total investments in securities	$	1,165,329,782	$	— $		— $	1,165,329,782
Principal U.S. Small-Cap Adaptive Multi-Factor ETF
Common Stocks*	$	5,656,448	$	— $		— $	5,656,448
Investment Companies		19,248		—		—	19,248
Total investments in securities	$	5,675,696	$	— $		— $	5,675,696
Principal U.S. Small-Cap Multi-Factor ETF
Common Stocks*	$	191,929,940	$	— $		— $	191,929,940
Investment Companies		832,629		—		—	832,629
Total investments in securities	$	192,762,569	$	— $		— $	192,762,569
Principal Value ETF
Common Stocks*	$	32,192,766	$	— $		— $	32,192,766
Investment Companies		125,551		—		—	125,551
Total investments in securities	$	32,318,317	$	— $		— $	32,318,317
* For additional detail regarding sector classifications, please see the Schedules of Investments.

The Funds’ Schedules of Investments for the period ended March 31, 2023 has not been audited. This report is provided for the general information of the Funds’ shareholders. For more information regarding the Funds and their holdings, please see the Funds’ prospectus.

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