BlackRock

U.S.

Mortgage

Portfolio

2

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

January

31,

2023

Security

Par

(000)

Par

(000)

Value

Asset-Backed

Securities

510

Loan

Acquisition

Trust,

Series

2020-1,

Class

A,

5.11%,

09/25/60

(a)(b)

.........

USD

1,137

$

1,063,069

Ajax

Mortgage

Loan

Trust

(b)

Series

2018-A,

Class

B,

0.00%,

04/25/58

2

1,925

Series

2020-A,

Class

A,

2.37%,

12/25/59

(a)

1,511

1,480,678

Series

2020-A,

Class

B,

3.50%,

12/25/59

(a)

233

226,465

Series

2020-A,

Class

C,

0.00%,

12/25/59

549

339,249

Series

2020-C,

Class

A,

2.25%,

09/27/60

(a)

80

77,710

Series

2020-C,

Class

B,

5.00%,

09/27/60

(a)

150

138,573

Series

2020-C,

Class

C,

0.00%,

09/27/60

471

392,628

Series

2020-D,

Class

A,

2.25%,

06/25/60

(a)

337

322,987

Series

2020-D,

Class

B,

5.00%,

06/25/60

(a)

210

193,999

Series

2020-D,

Class

C,

0.00%,

06/25/60

496

422,588

Series

2021-E,

Class

B3,

3.75%,

12/25/60

(c)

382

146,576

Series

2021-E,

Class

XS,

0.00%,

12/25/60

(c)

5,586

229,051

Series

2021-F,

Class

A,

1.87%,

06/25/61

(a)

2,639

2,384,853

Series

2021-F,

Class

B,

3.75%,

06/25/61

(a)

216

193,619

Series

2021-F,

Class

C,

0.00%,

06/25/61

(d)

403

368,779

Series

2021-G,

Class

A,

1.87%,

06/25/61

(c)

1,856

1,708,346

Series

2021-G,

Class

B,

3.75%,

06/25/61

(c)

256

220,202

Series

2021-G,

Class

C,

0.00%,

06/25/61

464

473,568

AREIT

Trust

(b)(c)

Series

2021-CRE5,

Class

A,

(LIBOR

USD

1

Month

+

1.08%),

5.54%,

11/17/38

...

510

490,356

Series

2022-CRE6,

Class

A,

(SOFR

30

Day

Average

+

1.25%),

5.56%,

01/16/37

..

609

584,987

Bayview

Financial

Revolving

Asset

Trust,

Series

2004-B,

Class

A1,

(LIBOR

USD

1

Month

+

1.00%),

5.55%,

05/28/39

(b)(c)

...

1,935

1,547,892

BDS

Ltd.,

Series

2021-FL9,

Class

A,

(LIBOR

USD

1

Month

+

1.07%),

5.54%,

11/16/38

(b)(c)

680

656,218

Bear

Stearns

Asset-Backed

Securities

I

Trust

(c)

Series

2006-HE8,

Class

1A3,

(LIBOR

USD

1

Month

+

0.26%),

5.03%,

10/25/36

..

1,200

1,078,792

Series

2007-HE2,

Class

22A,

(LIBOR

USD

1

Month

+

0.14%),

4.65%,

03/25/37

..

559

512,539

BSPRT

Issuer

Ltd.,

Series

2022-FL8,

Class

A,

(SOFR

30

Day

Average

+

1.50%),

5.78%,

02/15/37

(b)(c)

....................

730

715,296

Carrington

Mortgage

Loan

Trust,

Series

2007-

FRE1,

Class

M1,

(LIBOR

USD

1

Month

+

0.50%),

5.01%,

02/25/37

(c)

..........

1,738

1,263,785

Countrywide

Asset-Backed

Certificates,

Series

2002-BC3,

Class

M2,

(LIBOR

USD

1

Month

+

1.73%),

6.23%,

05/25/32

(c)

.........

1,271

1,201,794

Credit-Based

Asset

Servicing

&

Securitization

LLC,

Series

2007-CB6,

Class

A4,

(LIBOR

USD

1

Month

+

0.34%),

4.38%,

07/25/37

(b)(c)

1,596

1,067,192

CWABS

Asset-Backed

Certificates

Trust

(c)

Series

2006-18,

Class

M1,

(LIBOR

USD

1

Month

+

0.45%),

4.96%,

03/25/37

...

1,545

1,341,533

Series

2006-22,

Class

M1,

(LIBOR

USD

1

Month

+

0.23%),

4.74%,

05/25/47

...

2,076

1,786,476

Series

2007-BC3,

Class

1A,

(LIBOR

USD

1

Month

+

0.18%),

4.69%,

11/25/47

...

684

658,141

CWABS,

Inc.

Asset-Backed

Certificates

Trust,

Series

2004-6,

Class

2A4,

(LIBOR

USD

1

Month

+

0.90%),

5.41%,

11/25/34

(c)

.....

8

7,437

Dryden

XXVIII

Senior

Loan

Fund,

Series

2013-

28A,

Class

A1LR,

(LIBOR

USD

3

Month

+

1.20%),

5.81%,

08/15/30

(b)(c)

.........

996

992,095

FS

Rialto

Issuer

LLC

(b)(c)

Series

2022-FL6,

Class

A,

(1

Month

CME

Term

SOFR

+

2.58%),

7.07%,

08/17/37

350

349,997

Security

Par

(000)

Par

(000)

Value

Asset-Backed

Securities

(continued)

Series

2022-FL7,

Class

A,

(1

Month

CME

Term

SOFR

+

2.90%),

6.81%,

10/19/39

USD

540

$

539,950

GSAA

Home

Equity

Trust,

Series

2006-5,

Class

1A1,

(LIBOR

USD

1

Month

+

0.36%),

4.87%,

03/25/36

(c)

................

103

32,804

Home

Partners

of

America

Trust,

Series

2021-

3,

Class

F,

4.24%,

01/17/41

(b)

.........

1,863

1,571,225

KREF

Ltd.,

Series

2022-FL3,

Class

A,

(1

Month

CME

Term

SOFR

+

1.45%),

5.94%,

02/17/39

(b)(c)

....................

2,950

2,889,742

Legacy

Mortgage

Asset

Trust,

Series

2019-

SL2,

Class

A,

3.38%,

02/25/59

(b)(c)

.....

1,248

1,167,762

Long

Beach

Mortgage

Loan

Trust

(c)

Series

2006-1,

Class

2A4,

(LIBOR

USD

1

Month

+

0.60%),

5.11%,

02/25/36

...

657

547,117

Series

2006-7,

Class

2A3,

(LIBOR

USD

1

Month

+

0.32%),

4.83%,

08/25/36

...

1,650

696,658

Morgan

Stanley

IXIS

Real

Estate

Capital

Trust,

Series

2006-1,

Class

A3,

(LIBOR

USD

1

Month

+

0.30%),

4.81%,

07/25/36

(c)

....

418

177,494

Mosaic

Solar

Loan

Trust,

Series

2019-2A,

Class

A,

2.88%,

09/20/40

(b)

..........

43

38,322

New

Residential

Mortgage

Loan

Trust,

Series

2022-SFR1,

Class

F,

4.44%,

02/17/39

(b)

..

2,739

2,419,019

Option

One

Mortgage

Loan

Trust,

Series

2007-

FXD1,

Class

2A1,

5.87%,

01/25/37

(a)

....

1,058

904,300

Progress

Residential

Trust

(b)

Series

2019-SFR4,

Class

G,

3.93%,

10/17/36

....................

2,000

1,906,386

Series

2020-SFR3,

Class

G,

4.11%,

10/17/27

....................

2,750

2,500,721

Series

2021-SFR10,

Class

F,

4.61%,

12/17/40

....................

1,499

1,265,168

Series

2021-SFR11,

Class

F,

4.42%,

01/17/39

....................

2,000

1,642,801

Series

2022-SFR1,

Class

F,

4.88%,

02/17/41

....................

2,500

2,072,482

RASC

Series

Trust,

Series

2006-EMX9,

Class

1A4,

(LIBOR

USD

1

Month

+

0.24%),

4.99%,

11/25/36

(c)

................

1,196

948,287

Structured

Asset

Securities

Corp.

Mortgage

Loan

Trust,

Series

2007-MN1A,

Class

A1,

(LIBOR

USD

1

Month

+

0.23%),

4.74%,

01/25/37

(b)(c)

....................

1,200

724,159

Tricon

American

Homes

Trust,

Series

2020-

SFR1,

Class

F,

4.88%,

07/17/38

(b)

.....

1,050

997,765

Total

Asset-Backed

Securities

—

14.3%

(Cost:

$50,278,298)

..............................

47,681,557

Non-Agency

Mortgage-Backed

Securities

Collateralized

Mortgage

Obligations

—

13.2%

Alternative

Loan

Trust

Series

2005-54CB,

Class

3A1,

5.13%,

11/25/35

....................

1,209

678,500

Series

2006-45T1,

Class

2A7,

(LIBOR

USD

1

Month

+

0.34%),

4.85%,

02/25/37

(c)

.

1,485

626,067

Banc

of

America

Mortgage

Trust,

Series

2005-I,

Class

2A5,

3.86%,

10/25/35

(c)

........

81

74,210

Barclays

Mortgage

Trust

(b)

Series

2021-NPL1,

Class

A,

2.00%,

11/25/51

(a)

...................

3,099

2,952,952

Series

2021-NPL1,

Class

B,

4.62%,

11/25/51

(a)

...................

177

171,730

Series

2021-NPL1,

Class

C,

0.00%,

11/25/51

(d)

...................

397

359,903

BlackRock

U.S.

Mortgage

Portfolio

3

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Security

Par

(000)

Par

(000)

Value

Collateralized

Mortgage

Obligations

(continued)

BCAP

LLC

Trust,

Series

2012-RR3,

Class

3A8,

3.37%,

07/26/37

(b)(c)

...............

USD

1,466

$

1,276,780

Bear

Stearns

ALT-A

Trust,

Series

2007-1,

Class

1A1,

(LIBOR

USD

1

Month

+

0.32%),

4.83%,

01/25/47

(c)

................

678

535,811

CFMT

LLC,

Series

2020-HB4,

Class

M4,

4.95%,

12/26/30

(b)(c)

...............

900

840,114

ChaseFlex

Trust,

Series

2007-1,

Class

2A7,

6.00%,

02/25/37

.................

1,904

765,663

CHL

Mortgage

Pass-Through

Trust

Series

2005-17,

Class

1A6,

5.50%,

09/25/35

26

22,247

Series

2006-OA4,

Class

A1,

(Federal

Reserve

US

12

Month

Cumulative

Average

1

Year

CMT

+

0.96%),

3.39%,

04/25/46

(c)

...................

1,241

394,812

Citigroup

Mortgage

Loan

Trust,

Series

2015-A,

Class

B4,

4.50%,

06/25/58

(b)(c)

........

1,394

1,251,143

CitiMortgage

Alternative

Loan

Trust,

Series

2007-A5,

Class

1A6,

6.00%,

05/25/37

...

564

515,893

CSMC

Trust

(b)

Series

2010-6R,

Class

2A6B,

6.25%,

07/26/37

....................

666

674,738

Series

2022-ATH2,

Class

A1,

4.55%,

05/25/67

(c)

...................

1,143

1,118,890

GSR

Mortgage

Loan

Trust,

Series

2006-9F,

Class

3A1,

6.25%,

10/25/36

.........

585

526,502

Homeward

Opportunities

Fund

I

Trust

(b)(c)

Series

2020-2,

Class

B1,

5.45%,

05/25/65

1,985

1,805,774

Series

2020-2,

Class

M1,

3.90%,

05/25/65

2,625

2,306,036

Impac

Secured

Assets

Trust,

Series

2006-1,

Class

1A2B,

(LIBOR

USD

1

Month

+

0.40%),

4.91%,

05/25/36

(c)

..........

1,126

832,358

IndyMac

INDX

Mortgage

Loan

Trust,

Series

2006-AR15,

Class

A1,

(LIBOR

USD

1

Month

+

0.24%),

4.75%,

07/25/36

(c)

.........

610

555,672

Lehman

XS

Trust,

Series

2007-16N,

Class

AF2,

(LIBOR

USD

1

Month

+

1.90%),

6.41%,

09/25/47

(c)

.....................

1,038

1,240,688

MCM

Trust

(d)

Series

2021-VFN1,  3.00%,

08/25/28

(b)

..

524

501,968

Series

2021-VFN1,  3.00%,

08/28/28

...

294

193,790

New

Residential

Mortgage

Loan

Trust

(b)(c)

Series

2019-NQM5,

Class

A1,

2.71%,

11/25/59

....................

2,246

2,087,327

Series

2020-RPL1,

Class

B3,

3.88%,

11/25/59

....................

2,500

1,945,263

RALI

Trust,

Series

2007-QS1,

Class

1A5,

(LIBOR

USD

1

Month

+

0.55%),

5.06%,

01/25/37

(c)

.....................

1,062

743,474

Reperforming

Loan

REMIC

Trust,

Series

2005-R3,

Class

AF,

(LIBOR

USD

1

Month

+

0.40%),

4.91%,

09/25/35

(b)(c)

.........

164

142,046

Residential

Asset

Securitization

Trust

(c)

Series

2006-A7CB,

Class

2A2,

(LIBOR

USD

1

Month

+

0.55%),

5.06%,

07/25/36

..

2,601

500,401

Series

2006-A7CB,

Class

2A5,

(LIBOR

USD

1

Month

+

0.25%),

4.76%,

07/25/36

..

569

102,208

Series

2006-A7CB,

Class

2A6,

(LIBOR

USD

1

Month

+

54.00%),

17.95%,

07/25/36

457

548,756

RFMSI

Trust

(c)

Series

2005-SA3,

Class

1A,

3.58%,

08/25/35

....................

1,829

898,384

Series

2006-SA2,

Class

2A1,

4.86%,

08/25/36

....................

99

69,161

RMF

Buyout

Issuance

Trust,

Series

2021-HB1,

Class

M6,

6.00%,

11/25/31

(b)(c)(d)

.......

1,609

940,952

Security

Par

(000)

Par

(000)

Value

Collateralized

Mortgage

Obligations

(continued)

Seasoned

Loans

Structured

Transaction

Trust

(b)

(c)

Series

2020-2,

Class

M1,

4.75%,

09/25/60

USD

3,320

$

3,163,830

Series

2020-3,

Class

M1,

4.75%,

04/26/60

2,500

2,398,408

Spruce

Hill

Mortgage

Loan

Trust

(b)

Series

2020-SH2,

Class

B1,

5.00%,

06/25/55

(c)

...................

2,764

2,545,037

Series

2022-SH1,

Class

A1A,

4.10%,

07/25/57

(a)

...................

1,339

1,290,227

TVC

Mortgage

Trust,

Series

2020-RTL1,

Class

A1,

3.47%,

09/25/24

(b)

.............

366

364,857

Verus

Securitization

Trust,

Series

2020-INV1,

Class

B1,

5.75%,

03/25/60

(b)(c)

........

1,100

1,044,711

WaMu

Mortgage

Pass-Through

Certificates

Trust,

Series

2007-OA5,

Class

2A,

(Federal

Reserve

US

12

Month

Cumulative

Average

1

Year

CMT

+

0.80%),

3.23%,

06/25/47

(c)

.

1,755

1,349,719

Washington

Mutual

Mortgage

Pass-Through

Certificates

WMALT

Trust

Series

2006-2,

Class

2CB,

6.50%,

03/25/36

763

532,409

Series

2006-AR8,

Class

2A,

(Federal

Reserve

US

12

Month

Cumulative

Average

1

Year

CMT

+

0.85%),

3.28%,

10/25/46

(c)

...................

115

94,749

Series

2007-5,

Class

A3,

7.00%,

06/25/37

216

129,123

Western

Mortgage

Reference

Notes

(b)(c)

Series

2021-CL2,

Class

M1,

(SOFR

30

Day

Average

+

3.15%),

7.46%,

07/25/59

..

1,512

1,501,768

Series

2021-CL2,

Class

M2,

(SOFR

30

Day

Average

+

3.70%),

8.01%,

07/25/59

..

1,521

1,510,813

44,125,864

Commercial

Mortgage-Backed

Securities

—

19.7%

1211

Avenue

of

the

Americas

Trust,

Series

2015-1211,

Class

A1A2,

3.90%,

08/10/35

(b)

370

351,446

280

Park

Avenue

Mortgage

Trust,

Series

2017-280P,

Class

E,

(LIBOR

USD

1

Month

+

2.12%),

6.36%,

09/15/34

(b)(c)

.........

150

136,595

Alen

Mortgage

Trust,

Series

2021-ACEN,

Class

D,

(LIBOR

USD

1

Month

+

3.10%),

7.56%,

04/15/34

(b)(c)

....................

276

218,994

Arbor

Multifamily

Mortgage

Securities

Trust,

Series

2020-MF1,

Class

E,

1.75%,

05/15/53

(b)

.....................

750

431,197

Ashford

Hospitality

Trust

(b)(c)

Series

2018-ASHF,

Class

D,

(LIBOR

USD

1

Month

+

2.10%),

6.56%,

04/15/35

...

280

259,887

Series

2018-ASHF,

Class

E,

(LIBOR

USD

1

Month

+

3.10%),

7.56%,

04/15/35

...

470

433,430

BAMLL

Commercial

Mortgage

Securities

Trust

(b)(c)

Series

2018-DSNY,

Class

A,

(LIBOR

USD

1

Month

+

0.85%),

5.31%,

09/15/34

...

529

524,343

Series

2018-DSNY,

Class

D,

(LIBOR

USD

1

Month

+

1.70%),

6.16%,

09/15/34

...

160

155,578

BANK

Series

2021-BN35,

Class

A5,

2.29%,

06/15/64

....................

730

609,626

Series

2021-BN38,

Class

A5,

2.52%,

12/15/64

....................

1,700

1,441,680

Bayview

Commercial

Asset

Trust

(b)(c)

Series

2006-3A,

Class

A2,

(LIBOR

USD

1

Month

+

0.45%),

4.96%,

10/25/36

...

846

795,224

Series

2006-4A,

Class

A1,

(LIBOR

USD

1

Month

+

0.35%),

4.85%,

12/25/36

...

661

616,586

BlackRock

U.S.

Mortgage

Portfolio

4

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

BBCMS

Mortgage

Trust

Series

2017-DELC,

Class

F,

(LIBOR

USD

1

Month

+

3.63%),

8.08%,

08/15/36

(b)(c)

.

USD

618

$

609,310

Series

2020-C7,

Class

A5,

2.04%,

04/15/53

1,950

1,641,442

Series

2020-C7,

Class

D,

3.60%,

04/15/53

(b)

(c)

.........................

500

339,899

Series

2021-C12,

Class

A5,

2.69%,

11/15/54

3,000

2,577,578

Series

2022-C18,

Class

ASB,

5.95%,

12/15/55

(c)

...................

650

702,328

Beast

Mortgage

Trust,

Series

2021-SSCP,

Class

A,

(LIBOR

USD

1

Month

+

0.75%),

5.21%,

04/15/36

(b)(c)

...............

290

280,206

Benchmark

Mortgage

Trust

Series

2019-B15,

Class

A5,

2.93%,

12/15/72

2,500

2,232,778

Series

2022-B35,

Class

A5,

4.45%,

05/15/55

(c)

...................

2,500

2,472,258

BFLD

Trust,

Series

2020-EYP,

Class

E,

(LIBOR

USD

1

Month

+

3.70%),

8.16%,

10/15/35

(b)(c)

120

98,704

BHMS,

Series

2018-ATLS,

Class

C,

(LIBOR

USD

1

Month

+

1.90%),

6.36%,

07/15/35

(b)(c)

269

256,209

BPR

Trust

(b)(c)

Series

2021-TY,

Class

A,

(LIBOR

USD

1

Month

+

1.05%),

5.51%,

09/15/38

...

1,000

955,880

Series

2021-TY,

Class

E,

(LIBOR

USD

1

Month

+

3.60%),

8.06%,

09/15/38

...

750

704,828

Series

2022-SSP,

Class

A,

(1

Month

CME

Term

SOFR

+

3.00%),

7.48%,

05/15/39

370

367,413

BX

Commercial

Mortgage

Trust

(b)(c)

Series

2019-XL,

Class

D,

(1

Month

CME

Term

SOFR

+

1.56%),

6.04%,

10/15/36

1,190

1,167,587

Series

2020-VIV3,

Class

B,

3.54%,

03/09/44

683

595,376

Series

2021-SOAR,

Class

G,

(LIBOR

USD

1

Month

+

2.80%),

7.26%,

06/15/38

...

248

236,419

Series

2021-VINO,

Class

F,

(LIBOR

USD

1

Month

+

2.80%),

7.26%,

05/15/38

...

175

164,922

Series

2021-XL2,

Class

A,

(LIBOR

USD

1

Month

+

0.69%),

5.15%,

10/15/38

...

3,191

3,101,826

Series

2022-CSMO,

Class

C,

(1

Month

CME

Term

SOFR

+

3.89%),

8.37%,

06/15/27

260

258,861

BX

Trust

(b)

Series

2019-OC11,

Class

A,

3.20%,

12/09/41

....................

1,410

1,238,905

Series

2019-OC11,

Class

E,

3.94%,

12/09/41

(c)

...................

123

99,064

Series

2021-ARIA,

Class

G,

(LIBOR

USD

1

Month

+

3.14%),

7.60%,

10/15/36

(c)

..

156

142,936

Series

2021-LBA,

Class

AJV,

(LIBOR

USD

1

Month

+

0.80%),

5.26%,

02/15/36

(c)

..

705

682,312

Series

2021-SDMF,

Class

A,

(LIBOR

USD

1

Month

+

0.59%),

5.05%,

09/15/34

(c)

..

573

556,701

Series

2021-VIEW,

Class

D,

(LIBOR

USD

1

Month

+

2.90%),

7.36%,

06/15/36

(c)

..

275

254,583

Series

2022-GPA,

Class

D,

(1

Month

CME

Term

SOFR

+

4.06%),

8.54%,

10/15/39

(c)

300

298,873

Series

2022-LBA6,

Class

A,

(1

Month

CME

Term

SOFR

+

1.00%),

5.48%,

01/15/39

(c)

700

685,121

Series

2022-VAMF,

Class

F,

(1

Month

CME

Term

SOFR

+

3.30%),

7.78%,

01/15/39

(c)

450

419,577

BXP

Trust,

Series

2021-601L,

Class

D,

2.78%,

01/15/44

(b)(c)

....................

540

354,473

CFK

Trust,

Series

2020-MF2,

Class

B,

2.79%,

03/15/39

(b)

.....................

336

295,473

Citigroup

Commercial

Mortgage

Trust,

Series

2019-PRM,

Class

E,

4.73%,

05/10/36

(b)(c)

.

100

99,543

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

Cold

Storage

Trust,

Series

2020-ICE5,

Class

A,

(LIBOR

USD

1

Month

+

0.90%),

5.36%,

11/15/37

(b)(c)

....................

USD

688

$

677,749

Commercial

Mortgage

Trust

Series

2014-UBS2,

Class

A5,

3.96%,

03/10/47

....................

345

338,990

Series

2015-CR25,

Class

A3,

3.51%,

08/10/48

....................

535

518,174

Series

2015-CR25,

Class

C,

4.52%,

08/10/48

(c)

...................

255

231,564

Series

2017-PANW,

Class

A,

3.24%,

10/10/29

(b)

...................

1,580

1,487,966

Credit

Suisse

Mortgage

Capital

Certificates,

Series

2019-ICE4,

Class

E,

(LIBOR

USD

1

Month

+

2.15%),

6.61%,

05/15/36

(b)(c)

...

280

275,071

CSAIL

Commercial

Mortgage

Trust

Series

2018-C14,

Class

A4,

4.42%,

11/15/51

(c)

...................

600

582,938

Series

2019-C16,

Class

C,

4.24%,

06/15/52

(c)

...................

511

419,473

Series

2019-C17,

Class

C,

3.93%,

09/15/52

(d)

...................

392

329,480

CSMC

Trust

(b)(c)

Series

2020-FACT,

Class

F,

(LIBOR

USD

1

Month

+

6.16%),

10.62%,

10/15/37

...

600

549,739

Series

2021-980M,

Class

E,

3.54%,

07/15/31

....................

365

271,814

Series

2021-BHAR,

Class

E,

(LIBOR

USD

1

Month

+

3.50%),

7.96%,

11/15/38

...

300

281,303

DBGS

Mortgage

Trust,

Series

2018-BIOD,

Class

F,

(LIBOR

USD

1

Month

+

2.00%),

6.46%,

05/15/35

(b)(c)

...............

210

202,334

Extended

Stay

America

Trust,

Series

2021-

ESH,

Class

F,

(LIBOR

USD

1

Month

+

3.70%),

8.16%,

07/15/38

(b)(c)

.........

402

385,074

GS

Mortgage

Securities

Corp.

II,

Series

2005-

ROCK,

Class

A,

5.37%,

05/03/32

(b)

.....

335

328,809

GS

Mortgage

Securities

Corp.

Trust

(b)(c)

Series

2021-DM,

Class

F,

(LIBOR

USD

1

Month

+

3.44%),

7.90%,

11/15/36

...

240

224,623

Series

2021-IP,

Class

E,

(LIBOR

USD

1

Month

+

3.55%),

8.01%,

10/15/36

...

300

278,366

Series

2021-STAR,

Class

B,

(LIBOR

USD

1

Month

+

1.40%),

5.86%,

12/15/36

...

870

842,838

Series

2022-AGSS,

Class

A,

(1

Month

CME

Term

SOFR

+

2.69%),

7.17%,

11/15/27

380

384,243

Hawaii

Hotel

Trust,

Series

2019-MAUI,

Class

A,

(LIBOR

USD

1

Month

+

1.15%),

5.61%,

05/15/38

(b)(c)

....................

250

245,614

Hilton

USA

Trust,

Series

2016-HHV,

Class

C,

4.19%,

11/05/38

(b)(c)

...............

519

478,970

HONO

Mortgage

Trust

(b)(c)

Series

2021-LULU,

Class

E,

(LIBOR

USD

1

Month

+

3.35%),

7.81%,

10/15/36

...

590

541,897

Series

2021-LULU,

Class

F,

(LIBOR

USD

1

Month

+

4.40%),

8.86%,

10/15/36

...

410

373,690

Hudson

Yards

Mortgage

Trust,

Series

2019-

30HY,

Class

D,

3.44%,

07/10/39

(b)(c)

....

208

163,065

IMT

Trust,

Series

2017-APTS,

Class

BFX,

3.50%,

06/15/34

(b)(c)

...............

1,250

1,193,998

JPMorgan

Chase

Commercial

Mortgage

Securities

Trust

(b)

Series

2016-NINE,

Class

A,

2.85%,

09/06/38

(c)

...................

640

579,044

Series

2018-AON,

Class

A,

4.13%,

07/05/31

610

571,592

BlackRock

U.S.

Mortgage

Portfolio

5

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

Series

2021-MHC,

Class

A,

(LIBOR

USD

1

Month

+

0.80%),

5.26%,

04/15/38

(c)

..

USD

576

$

568,474

Series

2022-ACB,

Class

D,

(SOFR

30

Day

Average

+

2.90%),

7.18%,

03/15/39

(c)

.

600

581,982

Series

2022-CGSS,

Class

A,

(1

Month

CME

Term

SOFR

+

2.47%),

6.95%,

12/15/36

(c)

560

559,638

Series

2022-NXSS,

Class

A,

(1

Month

CME

Term

SOFR

+

2.18%),

6.66%,

08/15/39

(c)

539

538,828

Series

2022-OPO,

Class

D,

3.45%,

01/05/39

(c)

...................

350

259,621

KKR

Industrial

Portfolio

Trust,

Series

2021-

KDIP,

Class

A,

(1

Month

CME

Term

SOFR

+

0.66%),

5.14%,

12/15/37

(b)(c)

.........

631

616,551

Life

Mortgage

Trust,

Series

2021-BMR,

Class

F,

(LIBOR

USD

1

Month

+

2.35%),

6.81%,

03/15/38

(b)(c)

....................

164

157,167

Med

Trust,

Series

2021-MDLN,

Class

G,

(LIBOR

USD

1

Month

+

5.25%),

9.71%,

11/15/38

(b)(c)

....................

244

225,656

MF1

Multifamily

Housing

Mortgage

Loan

Trust,

Series

2021-W10,

Class

G,

(1

Month

CME

Term

SOFR

+

4.22%),

8.70%,

12/15/34

(b)(c)(d)

300

277,500

MFT

Trust,

Series

2020-ABC,

Class

C,

3.48%,

02/10/42

(b)(c)

....................

192

142,647

MHC

Commercial

Mortgage

Trust,

Series

2021-MHC,

Class

A,

(LIBOR

USD

1

Month

+

0.80%),

5.26%,

04/15/38

(b)(c)

.........

166

163,041

Morgan

Stanley

Bank

of

America

Merrill

Lynch

Trust,

Series

2015-C26,

Class

A5,

3.53%,

10/15/48

......................

1,103

1,058,943

Morgan

Stanley

Capital

I

Trust

Series

2014-150E,

Class

A,

3.91%,

09/09/32

(b)

...................

595

535,030

Series

2017-HR2,

Class

D,

2.73%,

12/15/50

(b)

...................

555

388,994

Series

2018-H4,

Class

A4,

4.31%,

12/15/51

1,824

1,778,488

Series

2018-SUN,

Class

A,

(LIBOR

USD

1

Month

+

0.90%),

5.36%,

07/15/35

(b)(c)

.

595

585,311

MSCG

Trust,

Series

2018-SELF,

Class

F,

(LIBOR

USD

1

Month

+

3.05%),

7.51%,

10/15/37

(b)(c)

....................

270

259,132

Natixis

Commercial

Mortgage

Securities

Trust,

Series

2018-FL1,

Class

A,

(LIBOR

USD

1

Month

+

0.95%),

5.41%,

06/15/35

(b)(c)

...

91

87,760

One

Bryant

Park

Trust,

Series

2019-OBP,

Class

A,

2.52%,

09/15/54

(b)

..............

1,072

908,371

PKHL

Commercial

Mortgage

Trust,

Series

2021-MF,

Class

NR,

(LIBOR

USD

1

Month

+

6.00%),

10.46%,

07/15/38

(b)(c)

.........

300

272,473

SMRT

Trust,

Series

2022-MINI,

Class

E,

(1

Month

CME

Term

SOFR

+

2.70%),

7.18%,

01/15/39

(b)(c)

....................

450

421,830

SREIT

Trust

(b)(c)

Series

2021-MFP,

Class

F,

(LIBOR

USD

1

Month

+

2.62%),

7.08%,

11/15/38

...

750

716,212

Series

2021-MFP2,

Class

A,

(LIBOR

USD

1

Month

+

0.82%),

5.28%,

11/15/36

...

1,055

1,032,248

STWD

Trust,

Series

2021-FLWR,

Class

A,

(LIBOR

USD

1

Month

+

0.58%),

5.04%,

07/15/36

(b)(c)

....................

1,208

1,174,010

Velocity

Commercial

Capital

Loan

Trust

(b)(c)

Series

2019-3,

Class

M4,

3.68%,

10/25/49

1,330

1,101,232

Series

2019-3,

Class

M6,

6.03%,

10/25/49

1,501

1,151,069

Series

2020-1,

Class

M4,

3.54%,

02/25/50

753

615,524

Series

2021-4,

Class

M5,

5.68%,

12/26/51

1,970

1,489,061

Security

Par

(000)

Par

(000)

Value

Commercial

Mortgage-Backed

Securities

(continued)

Wells

Fargo

Commercial

Mortgage

Trust

Series

2016-NXS5,

Class

C,

4.98%,

01/15/59

(c)

...................

USD

133

$

115,800

Series

2018-1745,

Class

A,

3.75%,

06/15/36

(b)(c)

..................

1,990

1,752,175

Series

2018-C44,

Class

A4,

3.95%,

05/15/51

....................

1,650

1,588,269

Series

2021-C59,

Class

A5,

2.63%,

04/15/54

....................

500

426,817

WFRBS

Commercial

Mortgage

Trust

Series

2014-C21,

Class

A4,

3.41%,

08/15/47

....................

469

457,086

Series

2014-LC14,

Class

A4,

3.77%,

03/15/47

....................

598

588,582

WMRK

Commercial

Mortgage

Trust,

Series

2022-WMRK,

Class

A,

(1

Month

CME

Term

SOFR

+

2.79%),

7.27%,

11/15/27

(b)(c)

...

660

659,584

65,879,495

Interest

Only

Collateralized

Mortgage

Obligations

—

0.2%

(c)

Alternative

Loan

Trust,

Series

2006-45T1,

Class

2A8,

(LIBOR

USD

1

Month

+

6.60%),

2.09%,

02/25/37

.................

743

145,990

GSR

Mortgage

Loan

Trust,

Series

2007-3F,

Class

4A2,

(LIBOR

USD

1

Month

+

6.70%),

2.19%,

05/25/37

.................

3,924

622,008

767,998

Interest

Only

Commercial

Mortgage-Backed

Securities

—

0.5%

(c)

BANK,

Series

2017-BNK9,

Class

XA,

0.77%,

11/15/54

.......................

3,463

103,721

BBCMS

Mortgage

Trust

Series

2020-C7,

Class

XA,

1.62%,

04/15/53

3,007

217,254

Series

2020-C7,

Class

XB,

0.99%,

04/15/53

1,000

58,963

Benchmark

Mortgage

Trust,

Series

2020-B17,

Class

XB,

(LIBOR

USD

1

Month

+

0.00%),

0.53%,

03/15/53

.................

15,395

441,745

Citigroup

Commercial

Mortgage

Trust,

Series

2020-420K,

Class

X,

0.80%,

11/10/42

(b)

..

3,975

201,859

CSAIL

Commercial

Mortgage

Trust

Series

2018-C14,

Class

XA,

0.55%,

11/15/51

....................

1,113

28,070

Series

2019-C16,

Class

XA,

1.55%,

06/15/52

....................

3,910

279,448

UBS

Commercial

Mortgage

Trust,

Series

2019-

C17,

Class

XA,

1.47%,

10/15/52

......

3,226

226,584

Wells

Fargo

Commercial

Mortgage

Trust,

Series

2017-C41,

Class

XA,

1.15%,

11/15/50

.......................

3,661

155,344

1,712,988

Total

Non-Agency

Mortgage-Backed

Securities

—

33.6%

(Cost:

$120,924,727)

.............................

112,486,345

U.S.

Government

Sponsored

Agency

Securities

Collateralized

Mortgage

Obligations

—

0.3%

Federal

Home

Loan

Mortgage

Corp.,

Series

4161,

Class

BW,

2.50%, 02/15/43

.....

200

175,911

Federal

Home

Loan

Mortgage

Corp.

Variable

Rate

Notes,

Series

2411,

Class

FJ,

(LIBOR

USD

1

Month

+

0.35%),

4.81%, 12/15/29

(c)

2

2,106

Federal

National

Mortgage

Association

Series

2010-134,

Class

KZ,

4.50%, 12/25/40

102

98,431

Series

2010-141,

Class

LZ,

4.50%, 12/25/40

(d)

..............

209

181,395

Series

2011-131,

Class

LZ,

4.50%, 12/25/41

145

143,851

BlackRock

U.S.

Mortgage

Portfolio

6

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Security

Par

(000)

Par

(000)

Value

Collateralized

Mortgage

Obligations

(continued)

Federal

National

Mortgage

Association

Variable

Rate

Notes,

Series

2018-32,

Class

PS,

(LIBOR

USD

1

Month

+

7.23%),

1.98%, 05/25/48

(c)

................

USD

177

$

156,686

Government

National

Mortgage

Association,

Series

2019-29,

Class

HY,

3.50%, 03/20/49

100

92,121

Government

National

Mortgage

Association

Variable

Rate

Notes,

Series

2014-107,

Class

WX,

6.73%, 07/20/39

(c)

.............

184

193,564

1,044,065

Commercial

Mortgage-Backed

Securities

—

0.1%

Federal

Home

Loan

Mortgage

Corp.

Variable

Rate

Notes,

Series

2018-W5FX,

Class

CFX,

(LIBOR

USD

1

Month

+

0.00%),

3.79%, 04/25/28

(b)(c)

...............

288

243,809

Government

National

Mortgage

Association,

Series

2019-53,

Class

V,

2.75%, 08/16/31

183

168,838

412,647

Interest

Only

Collateralized

Mortgage

Obligations

—

0.7%

Federal

Home

Loan

Mortgage

Corp.

Series

4062,

Class

GI,

4.00%, 02/15/41

.

115

6,597

Series

4533,

Class

JI,

5.00%, 12/15/45

..

141

25,558

Series

5159,

Class

KI,

3.00%, 11/25/51

..

617

80,039

Series

5159,

Class

PI,

3.00%, 11/25/51

..

951

130,065

Series

5176,

Class

QI,

3.00%, 12/25/51

.

609

89,348

Federal

Home

Loan

Mortgage

Corp.

Variable

Rate

Notes

(c)

Series

4119,

Class

SC,

(LIBOR

USD

1

Month

+

6.15%),

1.69%, 10/15/42

...

699

78,091

Series

4901,

Class

CS,

(LIBOR

USD

1

Month

+

6.10%),

1.59%, 07/25/49

...

500

52,218

Series

4941,

Class

SH,

(LIBOR

USD

1

Month

+

5.95%),

1.44%, 12/25/49

...

448

48,552

Federal

National

Mortgage

Association

Series

2013-10,

Class

PI,

3.00%, 02/25/43

492

66,461

Series

2014-68,

Class

YI,

4.50%, 11/25/44

210

44,218

Series

2015-74,

Class

IA,

6.00%, 10/25/45

960

220,838

Series

2015-77,

6.00%, 10/25/45

......

1,145

235,848

Series

2017-68,

Class

IE,

4.50%, 09/25/47

659

110,685

Series

2021-23,

Class

CI,

3.50%, 07/25/46

661

109,624

Series

2021-41,

3.50%, 07/25/51

......

790

131,623

Federal

National

Mortgage

Association

Variable

Rate

Notes

(c)

Series

2016-60,

Class

SD,

(LIBOR

USD

1

Month

+

6.10%),

1.59%, 09/25/46

...

1,024

80,360

Series

2016-78,

Class

CS,

(LIBOR

USD

1

Month

+

6.10%),

1.59%, 05/25/39

...

1,326

98,291

Series

2017-70,

Class

SA,

(LIBOR

USD

1

Month

+

6.15%),

1.64%, 09/25/47

...

643

71,087

Series

2019-5,

Class

SA,

(LIBOR

USD

1

Month

+

6.10%),

1.59%, 03/25/49

...

800

77,523

Series

2019-25,

Class

SA,

(LIBOR

USD

1

Month

+

6.05%),

1.54%, 06/25/49

...

3,003

316,914

Series

2019-35,

Class

SA,

(LIBOR

USD

1

Month

+

6.10%),

1.59%, 07/25/49

...

390

40,865

Government

National

Mortgage

Association

Series

2017-139,

Class

IB,

4.50%, 09/20/47

520

93,837

Series

2017-144,

Class

DI,

4.50%, 09/20/47

353

63,536

Series

2021-104,

Class

IH,

3.00%, 06/20/51

1,087

167,666

Security

Par

(000)

Par

(000)

Value

Interest

Only

Collateralized

Mortgage

Obligations

(continued)

Government

National

Mortgage

Association

Variable

Rate

Notes,

Series

2017-101,

Class

SL,

(LIBOR

USD

1

Month

+

6.20%),

1.71%, 07/20/47

(c)

................

USD

430

$

51,126

2,490,970

Interest

Only

Commercial

Mortgage-Backed

Securities

—

0.3%

(c)

Federal

Home

Loan

Mortgage

Corp.

Multifamily

Structured

Pass-Through

Certificates

Variable

Rate

Notes

Series

K110,

Class

X1,

1.70%, 04/25/30

.

5,326

491,130

Series

K722,

Class

X1,

1.41%, 03/25/23

.

277

14

Government

National

Mortgage

Association

Variable

Rate

Notes

Series

2016-151,

0.85%, 06/16/58

.....

8,957

326,499

Series

2020-43,

1.26%, 11/16/61

......

2,164

154,899

972,542

Mortgage-Backed

Securities

—

59.9%

Federal

Home

Loan

Mortgage

Corp.

2.50%, 03/01/30

-

04/01/31

..........

624

594,410

3.00%, 09/01/27

-

12/01/46

..........

941

884,972

3.50%, 12/01/41

-

01/01/48

..........

1,216

1,175,190

4.00%, 08/01/40

-

12/01/45

..........

367

364,199

4.50%, 07/01/26

-

09/01/48

..........

493

500,613

5.00%, 05/01/35

-

02/01/42

..........

637

655,639

5.50%, 02/01/35

-

06/01/41

..........

354

372,215

6.00%, 08/01/28

-

11/01/39

..........

17

18,095

Federal

National

Mortgage

Association

3.50%, 11/01/46

.................

356

337,681

4.00%, 01/01/41

.................

28

27,548

6.00%, 07/01/39

.................

266

274,625

Federal

National

Mortgage

Association

Variable

Rate

Notes

(c)

3.06%, 09/01/27

.................

164

157,870

3.22%, 03/01/27

.................

498

483,399

Government

National

Mortgage

Association

2.00%, 02/15/53

(e)

................

3,624

3,131,504

2.50%, 02/15/53

(e)

................

3,690

3,288,820

3.00%, 02/15/45

-

01/20/51

..........

746

691,045

3.00%, 02/15/53

(e)

................

1,755

1,611,908

3.50%, 01/15/42

-

10/20/46

..........

897

865,291

3.50%, 02/15/53

(e)

................

3,300

3,119,978

4.00%, 04/20/39

-

06/20/50

..........

2,948

2,890,745

4.00%, 02/15/53

(e)

................

558

541,696

4.50%, 09/20/39

-

04/20/47

..........

1,600

1,626,568

4.50%, 02/15/53

(e)

................

8,700

8,637,469

5.00%, 12/15/34

-

07/20/44

..........

1,119

1,156,119

5.50%, 07/15/38

-

12/20/41

..........

383

400,953

6.50%, 10/15/38

-

02/20/41

..........

125

131,052

Uniform

Mortgage-Backed

Securities

1.50%, 02/25/38

-

02/25/53

(e)

.........

8,437

7,088,379

2.00%, 10/01/31

-

03/01/52

..........

8,790

7,485,508

2.00%, 02/25/38

-

02/25/53

(e)

.........

19,395

16,682,638

2.50%, 04/01/30

-

03/01/32

..........

1,006

957,077

2.50%, 02/25/38

-

02/25/53

(e)

.........

19,190

16,891,477

3.00%, 04/01/28

-

08/01/50

..........

2,989

2,854,312

3.00%, 02/25/53

(e)

................

4,880

4,432,387

3.50%, 11/01/27

-

04/01/48

..........

1,822

1,757,240

4.00%, 08/01/31

-

05/01/52

..........

5,668

5,569,217

4.00%, 02/25/53

(e)

................

2,697

2,604,570

4.50%, 07/01/24

-

10/01/52

..........

13,674

13,653,059

4.50%, 02/25/53

(e)

................

51,720

51,073,500

5.00%, 03/01/23

-

10/01/52

..........

7,709

7,809,530

5.00%, 02/25/53

(e)

................

26,242

26,338,357

BlackRock

U.S.

Mortgage

Portfolio

7

(Percentages

shown

are

based

on

Net

Assets)

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Security

Par

(000)

Par

(000)

Value

Mortgage-Backed

Securities

(continued)

5.50%, 06/01/24

-

03/01/40

..........

USD

528

$

552,826

6.00%, 12/01/32

-

09/01/40

..........

358

376,035

6.50%, 09/01/36

-

05/01/40

..........

92

97,117

200,162,833

Total

U.S.

Government

Sponsored

Agency

Securities

—

61.3%

(Cost:

$205,682,634)

.............................

205,083,057

Total

Long-Term

Investments

—

109.2%

(Cost:

$376,885,659)

.............................

365,250,959

Shares

Shares

Short-Term

Securities

Money

Market

Funds

—

0.5%

Dreyfus

Treasury

Prime

Cash

Management

Institutional

Shares,

4.28%

(f)

.........

1,827,462

1,827,462

Total

Money

Market

Funds

—

0.5%

(Cost:

$1,827,462)

..............................

1,827,462

Security

Par

(000)

Pa

r

(

000)

Value

U.S.

Treasury

Obligations

—

32.8%

U.S.

Treasury

Bills

(g)

4.01%, 02/02/23

.................

USD

327

$

326,964

4.16%, 02/16/23

.................

6,818

6,805,791

4.43%, 02/21/23

.................

2,923

2,915,824

4.24%, 03/02/23

.................

5,073

5,054,948

4.19%, 03/09/23

.................

145

144,352

4.21%, 03/23/23

.................

47,361

47,068,612

4.50%, 04/11/23

.................

1,602

1,588,317

4.56%, 04/13/23

.................

38,233

37,891,891

4.59%, 04/20/23

.................

7,792

7,715,427

Total

U.S.

Treasury

Obligations

—

32.8%

(Cost:

$109,533,203)

.............................

109,512,126

Total

Short-Term

Securities

—

33.3%

(Cost:

$111,360,665)

.............................

111,339,588

Total

Investments

Before

Options

Written

—

142.5%

(Cost:

$488,246,324

)

.............................

476,590,547

Total

Options

Written

—

(0.1)%

(Premium

Received

—

$(337,911))

...................

(330,588)

Total

Investments

Net

of

Options

Written

—

142.4%

(Cost:

$487,908,413

)

.............................

476,259,959

Liabilities

in

Excess

of

Other

Assets

—

(42.4)%

...........

(141,907,817)

Net

Assets

—

100.0%

..............................

$

334,352,142

(a)

Step

coupon

security.

Coupon

rate

will

either

increase

(step-up

bond)

or

decrease

(step-down

bond)

at

regular

intervals

until

maturity.

Interest

rate

shown

reflects

the

rate

currently

in

effect.

(b)

Security

exempt

from

registration

pursuant

to

Rule

144A

under

the

Securities

Act

of

1933,

as

amended.

These

securities

may

be

resold

in

transactions

exempt

from

registration

to

qualified

institutional

investors.

(c)

Variable

rate

security.

Interest

rate

resets

periodically.

The

rate

shown

is

the

effective

interest

rate

as

of

period

end.

Security

description

also

includes

the

reference

rate

and

spread

if

published

and

available.

(d)

Security

is

valued

using

significant

unobservable

inputs

and

is

classified

as

Level

3

in

the

fair

value

hierarchy.

(e)

Represents

or

includes

a

TBA

transaction.

(f)

Annualized

7-day

yield

as

of

period

end.

(g)

Rates

are

discount

rates

or

a

range

of

discount

rates

as

of

period

end.

BlackRock

U.S.

Mortgage

Portfolio

8

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Derivative

Financial

Instruments

Outstanding

as

of

Period

End

Futures

Contracts

Description

Number

of

Contracts

Expiration

Date

Notional

Amount

(000)

Value/

Unrealized

Appreciation

(Depreciation)

Long

Contracts

U.S.

Treasury

10

Year

Note

...................................................

6

03/22/23

$

689

$

1,679

U.S.

Treasury

10

Year

Ultra

Note

...............................................

12

03/22/23

1,460

28,485

U.S.

Treasury

Long

Bond

.....................................................

128

03/22/23

16,716

689,786

U.S.

Treasury

Ultra

Bond

.....................................................

60

03/22/23

8,584

510,836

U.S.

Treasury

2

Year

Note

....................................................

147

03/31/23

30,246

67,541

1,298,327

Short

Contracts

3

Month

SOFR

............................................................

3

03/14/23

717

1,362

U.S.

Treasury

5

Year

Note

....................................................

681

03/31/23

74,543

(859,496)

3

Month

SOFR

............................................................

3

06/20/23

714

(42)

3

Month

SOFR

............................................................

3

09/19/23

713

633

3

Month

SOFR

............................................................

3

12/19/23

714

108

(857,435)

$

440,892

OTC

Interest

Rate

Swaptions

Written

Paid

by

the

Fund

Received

by

the

Fund

Description

Rate

Frequency

Rate

Frequency

Counterparty

Expiration

Date

Exercise

Rate

Notional

Amount

(000)

Value

Call

10-Year

Interest

Rate

Swap

(a)

2.10%

Semi-Annual

1

day

SOFR

Annual

Bank

of

America

NA

03/17/23

2.10

%

USD

1,700

$

(86)

10-Year

Interest

Rate

Swap

(a)

3.15%

Semi-Annual

1

day

SOFR

Annual

Deutsche

Bank

AG

01/04/24

3.15

USD

2,250

(82,282)

(82,368)

Put

10-Year

Interest

Rate

Swap

(a)

1

day

SOFR

Annual

2.10%

Semi-Annual

Bank

of

America

NA

03/17/23

2.10

USD

1,700

(156,837)

2-Year

Interest

Rate

Swap

(a)

.

1

day

SOFR

Annual

4.15%

Semi-Annual

Deutsche

Bank

AG

12/11/23

4.15

USD

10,300

(30,349)

10-Year

Interest

Rate

Swap

(a)

1

day

SOFR

Annual

3.15%

Semi-Annual

Deutsche

Bank

AG

01/04/24

3.15

USD

2,250

(61,034)

(248,220)

$

(330,588)

(a)

Forward

settling

swaption.

Centrally

Cleared

Interest

Rate

Swap

s

Paid

by

the

Fund

Received

by

the

Fund

Rate

Frequency

Rate

Frequency

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

0.18%

Quarterly

1

day

EFFR

Quarterly

10/21/25

USD

159

$

15,048

$

—

$

15,048

1

day

SOFR

Quarterly

0.17%

Quarterly

10/21/25

USD

159

(15,214)

—

(15,214)

0.56%

Quarterly

1

day

EFFR

Quarterly

10/21/30

USD

47

8,398

—

8,398

1

day

SOFR

Quarterly

0.53%

Quarterly

10/21/30

USD

47

(8,566)

—

(8,566)

2.16%

Annual

1

day

SOFR

Annual

04/01/32

USD

1,500

127,010

—

127,010

2.65%

Annual

1

day

SOFR

Annual

06/02/32

USD

800

36,745

—

36,745

1

day

SOFR

Annual

3.64%

Annual

09/28/32

USD

1,500

52,742

2,939

49,803

$

216,163

$

2,939

$

213,224

BlackRock

U.S.

Mortgage

Portfolio

9

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Fair

Value

Hierarchy

as

of

Period

End

Various

inputs

are

used

in

determining

the

fair

value

of

financial

instruments.

These

inputs

to

valuation

techniques

are

categorized

into

a

fair

value

hierarchy

consisting

of

three

broad

levels

for

financial

reporting

purposes

as

follows:

Level

1

—

Unadjusted

price

quotations

in

active

markets/exchanges

for

identical

assets

or

liabilities

that

the

Fund

has

the

ability

to

access;

Level

2

—

Other

observable

inputs

(including,

but

not

limited

to,

quoted

prices

for

similar

assets

or

liabilities

in

markets

that

are

active,

quoted

prices

for

identical

or

similar

assets

or

liabilities

in

markets

that

are

not

active,

inputs

other

than

quoted

prices

that

are

observable

for

the

assets

or

liabilities

(such

as

interest

rates,

yield

curves,

volatilities,

prepayment

speeds,

loss

severities,

credit

risks

and

default

rates)

or

other

market-corroborated

inputs);

and

Level

3

—

Unobservable

inputs

based

on

the

best

information

available

in

the

circumstances,

to

the

extent

observable

inputs

are

not

available

(including

the

Valuation

Committee's

assumptions

used

in

determining

the

fair

value

of

financial

instruments).

The

hierarchy

gives

the

highest

priority

to

unadjusted

quoted

prices

in

active

markets

for

identical

assets

or

liabilities

(Level

1

measurements)

and

the

lowest

priority

to

unobservable

inputs

(Level

3

measurements).

Accordingly,

the

degree

of

judgment

exercised

in

determining

fair

value

is

greatest

for

instruments

categorized

in

Level

3.

The

inputs

used

to

measure

fair

value

may

fall

into

different

levels

of

the

fair

value

hierarchy.

In

such

cases,

for

disclosure

purposes,

the

fair

value

hierarchy

classification

is

determined

based

on

the

lowest

level

input

that

is

significant

to

the

fair

value

measurement

in

its

entirety.

Investments

classified

within

Level

3

have

significant

unobservable

inputs

used

by

the

Valuation

Committee

in

determining

the

price

for

Fair

Valued

Investments.

Level

3

investments

include

equity

or

debt

issued

by

privately

held

companies

or

funds.

There

may

not

be

a

secondary

market,

and/

or

there

are

a

limited

number

of

investors.

The

categorization

of

a

value

determined

for

financial

instruments

is

based

on

the

pricing

transparency

of

the

financial

instruments

and

is

not

necessarily

an

indication

of

the

risks

associated

with

investing

in

those

securities.

For

information

about

the

Fund’s

policy

regarding

valuation

of

financial

instruments,

refer

to

its

most

recent

financial

statements.

Certain

investments

of

the

Fund

were

fair

valued

using

net

asset

value

("NAV")

as

a

practical

expedient

as

no

quoted

market

value

is

available

and

therefore

have

been

excluded

from

the

fair

value

hierarchy.

The

following

table

summarizes

the

Fund’s

financial

instruments

categorized

in

the

fair

value

hierarchy.

The

breakdown

of

the

Fund's

financial

instruments

into

major

categories

is

disclosed

in

the

Schedule

of

Investments

above.

OTC

Credit

Default

Swap

s

—

Buy

Protection

Reference

Obligation/Index

Financing

Rate

Paid

by

the

Fund

Payment

Frequency

Counterparty

Termination

Date

Notional

Amount

(000)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

CMBX.NA.9.BBB-

.........

3.00

%

Monthly

J.P.

Morgan

Securities

LLC

09/17/58

USD

3,100

$

542,746

$

295,600

$

247,146

$

–

$

–

$

–

OTC

Credit

Default

Swap

s

—

Sell

Protection

Reference

Obligation/Index

Financing

Rate

Received

by

the

Fund

Payment

Frequency

Counterparty

Termination

Date

Credit

Rating

(a)

Notional

Amount

(000)

(b)

Value

Upfront

Premium

Paid

(Received)

Unrealized

Appreciation

(Depreciation)

CMBX.NA.9.A

........

2.00

%

Monthly

Goldman

Sachs

International

09/17/58

A

USD

275

$

(13,077)

$

(4,926)

$

(8,151)

CMBX.NA.9.A

........

2.00

Monthly

Morgan

Stanley

&

Co.

International

plc

09/17/58

A

USD

275

(13,077)

(5,003)

(8,074)

CMBX.NA.9.BBB-

.....

3.00

Monthly

Deutsche

Bank

AG

09/17/58

BBB-

USD

2,197

(384,615)

(229,293)

(155,322)

CMBX.NA.9.BBB-

.....

3.00

Monthly

Goldman

Sachs

International

09/17/58

BBB-

USD

1,012

(177,180)

(41,751)

(135,429)

CMBX.NA.15.BBB-

....

3.00

Monthly

Morgan

Stanley

&

Co.

International

plc

11/18/64

BBB-

USD

500

(87,842)

(92,062)

4,220

$

(675,791)

$

(373,035)

$

(302,756)

(a)

Using

the

rating

of

the

issuer

or

the

underlying

securities

of

the

index,

as

applicable,

provided

by

S&P

Global

Ratings.

(b)

The

maximum

potential

amount

the

Fund

may

pay

should

a

negative

credit

event

take

place

as

defined

under

the

terms

of

the

agreement.

The

following

reference

rates,

and

their

values

as

of

period

end,

are

used

for

security

descriptions:

Reference

Index

Reference

Rate

1

day

EFFR

.........................................

Effective

Federal

Funds

Rate

4.33

%

1

day

SOFR

.........................................

Secured

Overnight

Financing

Rate

4.31

BlackRock

U.S.

Mortgage

Portfolio

10

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Level

1

Level

2

Level

3

Total

Assets

Investments

Long-Term

Investments

Asset-Backed

Securities

....................................

$

—

$

47,312,778

$

368,779

$

47,681,557

Non-Agency

Mortgage-Backed

Securities

........................

—

109,882,752

2,603,593

112,486,345

U.S.

Government

Sponsored

Agency

Securities

....................

—

204,901,662

181,395

205,083,057

Short-Term

Securities

Money

Market

Funds

......................................

1,827,462

—

—

1,827,462

U.S.

Treasury

Obligations

...................................

—

109,512,126

—

109,512,126

$

1,827,462

$

471,609,318

$

3,153,767

$

476,590,547

Derivative

Financial

Instruments

(a)

Assets

Credit

contracts

...........................................

$

—

$

251,366

$

—

$

251,366

Interest

rate

contracts

.......................................

1,300,430

237,004

—

1,537,434

Liabilities

Credit

contracts

...........................................

—

(306,976)

—

(306,976)

Interest

rate

contracts

.......................................

(859,538)

(354,368)

—

(1,213,906)

$

440,892

$

(172,974)

$

—

$

267,918

(a)

Derivative

financial

instruments

are

swaps,

futures

contracts

and

options

written.

Swaps

and

futures

contracts

are

valued

at

the

unrealized

appreciation

(depreciation)

on

the

instrument

and

options

written

are

shown

at

value.

A

reconciliation

of

Level

3

financial

instruments

is

presented

when

the

Fund

had

a

significant

amount

of

Level

3

investments

and

derivative

financial

instruments

at

the

beginning

and/or

end

of

the

period

in

relation

to

net

assets.

The

following

table

is

a

reconciliation

of

Level

3

investments

for

which

significant

unobservable

inputs

were

used

in

determining

fair

value:

Asset-

Backed

Securities

Non-Agency

Mortgage-

Backed

Securities

U.S.

Government

Sponsored

Agency

Securities

Total

Investments

Assets

Opening

balance,

as

of

April

30,

2022

.....................................................................

$

2,132,033

$

3,113,100

$

1,508,483

$

6,753,616

Transfers

into

Level

3

(a)

..............................................................................

348,399

802,561

231,313

1,382,273

Transfers

out

of

Level

3

(b)

.............................................................................

(2,113,804)

—

(1,312,384)

(3,426,188)

Accrued

discounts/premiums

...........................................................................

946

2,106

(237)

2,815

Net

realized

gain

(loss)

..............................................................................

234

(150,050)

(14,960)

(164,776)

Net

change

in

unrealized

appreciation

(depreciation)

(c)

..........................................................

20,262

(548,385)

(26,494)

(554,617)

Purchases

.......................................................................................

—

101,015

4,652

105,667

Sales

..........................................................................................

(19,291)

(716,754)

(208,978)

(945,023)

Closing

balance,

as

of

January

31,

2023

...................................................................

$

368,779

$

2,603,593

$

181,395

$

3,153,767

Net

change

in

unrealized

appreciation

(depreciation)

on

investments

still

held

at

January

31,

2023

(c)

.............................

$

19,819

$

(590,606)

$

(28,957)

$

(599,744)

(a)

As

of

April

30,

2022,

the

Fund

used

observable

inputs

in

determining

the

value

of

certain

investments.

As

of

January

31,

2023,

the

Fund

used

significant

unobservable

inputs

in

determining

the

value

of

the

same

investments.

As

a

result,

investments

at

beginning

of

period

value

were

transferred

from

Level

2

to

Level

3

in

the

fair

value

hierarchy.

(b)

As

of

April

30,

2022,

the

Fund

used

significant

unobservable

inputs

in

determining

the

value

of

certain

investments.

As

of

January

31,

2023,

the

Fund

used

observable

inputs

in

determining

the

value

of

the

same

investments.

As

a

result,

investments

at

beginning

of

period

value

were

transferred

from

Level

3

to

Level

2

in

the

fair

value

hierarchy.

(c)

Any

difference

between

net

change

in

unrealized

appreciation

(depreciation)

and

net

change

in

unrealized

appreciation

(depreciation)

on

investments

still

held

at

January

31,

2023

is

generally

due

to

investments

no

longer

held

or

categorized

as

Level

3

at

period

end.

The

Fund’s

financial

instruments

that

are

categorized

as

Level

3

were

valued

utilizing

third

party

pricing

information

without

adjustment.

Such

valuations

are

based

on

unobservable

inputs.

A

significant

change

in

third

party

information

could

result

in

a

significantly

lower

or

higher

value

of

such

Level

3

financial

instruments.

Currency

Abbreviation

USD

United

States

Dollar

Fair

Value

Hierarchy

as

of

Period

End

(continued)

BlackRock

U.S.

Mortgage

Portfolio

11

Schedule

of

Investments

(unaudited)

(continued)

January

31,

2023

Portfolio

Abbreviation

CMT

Constant

Maturity

Treasury

CSMC

Credit

Suisse

Mortgage

Capital

CWABS

Countrywide

Asset-Backed

Certificates

EFFR

Effective

Federal

Funds

Rate

LIBOR

London

Interbank

Offered

Rate

OTC

Over-the-counter

REMIC

Real

Estate

Mortgage

Investment

Conduit

SOFR

Secured

Overnight

Financing

Rate