UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-K/A

(Amendment No. 1)

(Mark One)

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2023

OR

☐
TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from              to             

Commission file number: 001-36343

A10 NETWORKS, INC.

(Exact Name of Registrant as Specified in its Charter)

 

Delaware	20-1446869
(State or Other Jurisdiction of Incorporation or Organization)	(I.R.S. Employer Identification No.)

2300 Orchard Parkway, San Jose, California 95131

(Address of Principal Executive Offices and Zip Code)

(408) 325-8668

(Registrant’s Telephone Number, Including Area Code)

Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class	Trading Symbol	Name of Each Exchange on Which Registered
Common Stock, $.00001 Par Value	ATEN	New York Stock Exchange

Securities registered pursuant to Section 12(g) of the Act:

None.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes   ☒    No  ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.     Yes ☐    No   ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.     Yes  ☒    No   ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).     Yes  ☒    No   ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Large accelerated filer	☒	Accelerated filer	☐
Non-accelerated filer	☐	Smaller reporting company	☐
		Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the Registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ¨

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).  Yes   ☐   No   ☒

The aggregate market value of the registrant’s common stock held by non-affiliates of the registrant as of June 30, 2023 (the last business day of the registrant’s most recently completed second fiscal quarter) was approximately $1,017.7 million, based upon the closing sale price of such stock on the New York Stock Exchange. Solely for purposes of this disclosure, shares of common stock held by executive officers and directors of the Registrant as of such date, as well as shares held by entities affiliated with our executive officers and directors, have been excluded because such persons may be deemed to be affiliates. This determination of executive officers and directors as affiliates is not necessarily a conclusive determination for any other purposes.

As of February 16, 2024, the number of outstanding shares of the registrant’s common stock, $0.00001 par value per share, was 74,495,333.

DOCUMENTS INCORPORATED BY REFERENCE

No documents are incorporated by reference into this Annual Report on Form 10-K/A except those exhibits so incorporated as set forth in the exhibit index.

Audit Firm ID	Auditor Name	Auditor Location
248	GRANT THORNTON LLP	San Jose, California

EXPLANATORY NOTE

A10 Networks, Inc. (the “Company”) is filing this Amendment Number 1 on Form 10-K/A (“Amendment”) to its Annual Report on Form 10-K for the fiscal year ended December 31, 2023, as originally filed with the Securities and Exchange Commission on February 29, 2024 (the “Original Filing”), solely to replace Item 9B. Other Information – Insider Adoption of Termination of Trading Arrangements in the Original Filing.

This Amendment speaks as of the date of the Original Filing and does not reflect events occurring after the filing of the Original Filing or modify or update disclosures that may be affected by subsequent events. Accordingly, this Amendment should be read in conjunction with the Original Filing and with the Company’s filings made with the SEC subsequent to the filing of the Original Filing, including any amendment to those filings.

Pursuant to Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), this Amendment contains new certifications pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, which are attached hereto. Because no financial statements are contained within this Amendment, paragraphs 3, 4 and 5 of the certifications have been omitted.

PART II

Item 9B. Other Information

Insider Adoption or Termination of Trading Arrangements

On October 4, 2023, the trading plan of Dhrupad Trivedi, President, Chief Executive Officer and Chairman, dated June 12, 2023, intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act (“Rule 10b5-1(c)”) to sell up to 60,606 shares of our common stock between November 7, 2023 and November 9, 2023, subject to certain conditions, terminated, under which no shares were ultimately sold. Subsequently, on November 27, 2023, Mr. Trivedi adopted a trading plan intended to satisfy Rule 10b5-1(c) with respect to the sale of up to 60,606 shares of our common stock between March 5, 2024 and May 16, 2024 (unless earlier terminated pursuant to the terms of the plan or upon the date all shares under the plan are sold).

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PART IV

Item 15. Exhibits, Financial Statement Schedules

1. Financial Statements: The information concerning our financial statements and Report of Independent Registered Public Accounting Firm required by this Item is incorporated by reference in the Original Filing to the section of the Original Filing in Item 8, titled “Financial Statements and Supplementary Data.”

2. Financial Statement Schedules: No schedules are required.

3. The exhibits listed in the following Index to Exhibits are filed or incorporated by reference as part of this report.

Exhibit Number		Incorporated by Reference
	Description	Form	SEC File No.	Exhibit Number	Filing Date	Filed Herewith
3.1	Amended and Restated Certificate of Incorporation of the Registrant	8-K	001-36343	3.1	December 6, 2019
3.2	Amended and Restated Bylaws of the Registrant	8-K	001-36343	3.2	December 6, 2019
4.1	Form of common stock certificate of the Registrant	S-1/A	333-194015	4.1	March 10, 2014
4.2	Amended and Restated Investors’ Rights Agreement among the Registrant and certain holders of its capital stock, amended as of October 4, 2013	S-1/A	333-194015	4.2	March 10, 2014
4.3	Description of the Registrant’s securities	10-K	001-36343	4.3	March 10, 2020
10.1*	Form of Indemnification Agreement between the Registrant and each of its directors and executive officers	S-1/A	333-194015	10.1	March 10, 2014
10.2*	2008 Stock Plan and forms of agreements thereunder	10-Q	001-36343	10.2	May 13, 2014
10.3*	Amended and Restated 2014 Equity Incentive Plan	10-Q	001-36343	10.1	August 6, 2015
10.4*	Amended 2014 Employee Stock Purchase Plan	10-K	001-36343	10.4	March 10, 2020
10.5*	2014 Employee Stock Purchase Plan and forms of agreements thereunder	S-1/A	333-194015	10.5	March 10, 2014
10.6*	Form of Stock Option Agreement pursuant to the 2008 Stock Plan	10-Q	001-36343	10.2	August 4, 2014
10.7*	Form of Stock Option Agreement- Early Exercise pursuant to the 2008 Stock Plan	10-Q	001-36343	10.3	August 4, 2014
10.8*	Form of Stock Option Agreement pursuant to the Amended and Restated 2014 Equity Incentive Plan	10-Q	001-36343	10.4	August 4, 2014
10.9*	Form of Restricted Stock Unit Agreement pursuant to the Amended and Restated 2014 Equity Incentive Plan	10-Q	001-36343	10.5	August 4, 2014
10.10*	Offer Letter, dated November 12, 2019, by and between the Registrant and Dhrupad Trivedi	8-K	001-36343	10.2	November 21, 2019
10.11*	Form of CEO Change in Control and Severance Agreement	8-K	001-36343	10.3	November 21, 2019
10.13	Reseller Agreement, dated April 2, 2009, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.12	February 18, 2014
10.14	First Amendment to Reseller Agreement, dated May 19, 2011, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.13	February 18, 2014
10.15	Second Amendment to Reseller Agreement, dated April 1, 2011, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.14	February 18, 2014
10.16	Third Amendment to Reseller Agreement, dated April 1, 2011, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.15	February 18, 2014
10.17	Fourth Amendment to Reseller Agreement, dated October 3, 2011, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.16	February 18, 2014
10.18	Fifth Amendment to Reseller Agreement, dated April 2, 2012, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.17	February 18, 2014

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Exhibit Number		Incorporated by Reference
	Description	Form	SEC File No.	Exhibit Number	Filing Date	Filed Herewith
10.19	Sixth Amendment to Reseller Agreement, dated November 29, 2012, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.18	February 18, 2014
10.20	Seventh Amendment to Reseller Agreement, dated April 9, 2013, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.19	February 18, 2014
10.21	Eighth Amendment to Reseller Agreement, dated October 22, 2013, by and between the Registrant and NEC Corporation	S-1/A	333-194015	10.2	February 18, 2014
10.22	Ninth Amendment to Reseller Agreement, executed on April 22, 2014, by and between the Registrant and NEC Corporation	10-Q	001-36343	10.1	August 4, 2014
10.23	Manufacturing Services Agreement, dated December 8, 2006, by and between the Registrant and Lanner Electronics (USA)	S-1/A	333-194015	10.21	February 18, 2014
10.24	Amendment No. 1 to Manufacturing Services Agreement, dated June 27, 2013, by and between the Registrant and Lanner Electronics (USA)	S-1/A	333-194015	10.22	February 18, 2014
10.25	Contract Manufacturer Agreement, dated July 1, 2008, by and between the Registrant and AEWIN Technologies, Inc.	S-1/A	333-194015	10.23	February 18, 2014
10.26	Amendment No. 1 to Contract Manufacturer Agreement, dated June 30, 2014, by and between the Registrant and AEWIN Technologies, Inc.	10-K	001-36343	10.31	March 11, 2015
10.27*	Form of Change in Control and Severance Agreement	S-1/A	333-194015	10.25	March 10, 2014
10.28*	Executive Incentive Compensation Plan	10-K	001-6343	10.32	March 1, 2016
10.29	Sublease Agreement, dated May 2, 2019, by and between Marvell Corporation and the Registrant	10-Q	001-36343	10.1	May 8, 2019
10.30	Common Stock Repurchase Agreement, dated as of September 8, 2022, between A10 Networks, Inc. and Summit Partners Growth Equity Fund VIII-A, L.P., Summit Partners Growth Equity Fund VIII-B L.P., Summit Investors I, LLC and Summit Investors I (UK), L.P.	8-K	001-36343	10.1	September 9, 2022
21.1	List of subsidiaries of the Registrant	10-K	001-36343	21.1	March 10, 2020
23.1	Consent of Grant Thornton LLP, independent registered public accounting firm	10-K	001-36343	23.1	February 29, 2024
23.2	Consent of Armanino LLP, independent registered public accounting firm	10-K	001-36343	23.2	February 29, 2024
31.1	Certification of Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act					X
31.2	Certification of Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act					X
32.1 **	Certification of Chief Executive Officer pursuant to Section 906 of the Sarbanes-Oxley Act	10-K	001-36343	32.1	February 29, 2024
32.2 **	Certification of Chief Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act	10-K	001-36343	32.2	February 29, 2024
97	A10 Networks, Inc. Policy for the Recovery of Erroneously Awarded Compensation	10-K	001-36343	97	February 29, 2024
101	Inline XBRL ("iXBRL") for the information under Part II, Item 9B, “Other Information” of this Amendment No. 1 on Form 10-K/A					X
101.INS	XBRL Instance Document.	10-K	001-36343	101.INS	February 29, 2024
101.SCH	XBRL Taxonomy Extension Schema Document.	10-K	001-36343	101.SCH	February 29, 2024
101.CAL	XBRL Taxonomy Extension Calculation Linkbase Document.	10-K	001-36343	101.CAL	February 29, 2024
101.DEF	XBRL Taxonomy Extension Definition Linkbase Document.	10-K	001-36343	101.DEF	February 29, 2024
101.LAB	XBRL Taxonomy Extension Label Linkbase Document.	10-K	001-36343	101.LAB	February 29, 2024
101.PRE	XBRL Taxonomy Extension Presentation Linkbase Document.	10-K	001-36343	101.PRE	February 29, 2024

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Exhibit Number		Incorporated by Reference
	Description	Form	SEC File No.	Exhibit Number	Filing Date	Filed Herewith
104	Cover Page Interactive Data File (formatted as inline XBRL and contained in Exhibit 101)					X

* Indicates a management contract or compensatory plan.

** The certifications attached as Exhibit 32.1 and 32.2 that accompany this Annual Report on Form 10‑K/A are not deemed filed with the Securities and Exchange Commission and are not to be incorporated by reference into any filing of A10 Networks, Inc. under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, whether made before or after the date of this Annual Report on Form 10‑K/A, irrespective of any general incorporation language contained in such filing.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

     

		A10 NETWORKS, INC.
Date:	March 7, 2024	By:	/s/ Brian Becker
			Brian Becker
			Chief Financial Officer (Principal Accounting and Financial Officer)

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