Form 8-K
8-K — A10 Networks, Inc.
Accession: 0001193125-26-338817
Filed: 2026-08-07
Period: 2026-08-06
CIK: 0001580808
SIC: 3576 (COMPUTER COMMUNICATIONS EQUIPMENT)
Item: Other Events
Item: Financial Statements and Exhibits
Documents
8-K — d141648d8k.htm (Primary)
EX-5.1 (d141648dex51.htm)
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8-K
8-K (Primary)
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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 8-K
CURRENT REPORT
Pursuant to Section 13 or 15(d)
of The Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): August 6, 2026
A10 NETWORKS, INC.
(Exact name of registrant as specified in its charter)
Delaware
001-36343
20-1446869
(State or Other Jurisdiction
of Incorporation)
(Commission
File Number)
(I.R.S. Employer
Identification No.)
2300 Orchard Parkway
San Jose, CA
95131
(Address of principal executive offices)
(Zip Code)
(408) 325-8668
(Registrant’s telephone number, including area code)
N/A
(Former name or former address, if changed since last report.)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligations of the registrant under any of the following provisions:
☐
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240-13e-4(c))
Securities registered pursuant to Section 12(b) of the Act:
Title of each class
Trading
symbol(s)
Name of each exchange
on which registered
Common Stock, $0.00001 par value
ATEN
New York Stock Exchange
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).
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. ☐
Item 8.01
Other Events.
On August 6, 2026, A10 Networks, Inc. filed a prospectus supplement to its automatic shelf registration statement on Form S-3 (Registration No. 333-298099) with the Securities and Exchange Commission. This Current Report on Form 8-K is being filed solely for the purpose of filing the opinion of Pillsbury Winthrop Shaw Pittman LLP relating to the legality of the issuance and sale of the securities set forth in the prospectus supplement, which opinion is attached as Exhibit 5.1 hereto.
Item 9.01
Financial Statements and Exhibits.
(d) Exhibits
Exhibit
Description
5.1
Opinion of Pillsbury Winthrop Shaw Pittman LLP.
23.1
Consent of Pillsbury Winthrop Shaw Pittman LLP (included in Exhibit 5.1).
104.1
Cover Page Interactive Data File (embedded within the inline XBRL document).
SIGNATURE
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 hereunto duly authorized.
Date: August 6, 2026
A10 NETWORKS, INC.
By:
/s/ Scott Weber
Scott Weber
General Counsel
EX-5.1
EX-5.1
Filename: d141648dex51.htm · Sequence: 2
EX-5.1
Exhibit 5.1
PILLSBURY WINTHROP SHAW PITTMAN LLP
2400 Hanover Street, Palo Alto, California 94304
August 6, 2026
A10 Networks, Inc.
2300 Orchard Parkway
San Jose, California 95131
Ladies and Gentlemen:
We have acted as counsel for A10
Networks, Inc., a Delaware corporation (the “Company”), in connection with the potential sale by certain stockholders of the Company of up to 153,962 shares (the “Shares”) of common stock, having a par value of $0.00001,
of the Company pursuant to the Registration Statement on Form S-3 (Registration No. 333-298099)(the “Registration Statement”), filed by the Company with the
Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933 (the “Act”), and related prospectus, dated August 6, 2026, as supplemented by the prospectus supplement dated August 6, 2026
relating to the offer and sale of the Shares (as so supplemented, the “Prospectus”) relating to the registration of 153,962 shares (the “Shares”).
We have reviewed the Registration Statement, the Prospectus and such other agreements, documents, records, certificates and other materials, and have reviewed
and are familiar with such corporate proceedings and satisfied ourselves as to such other matters, as we have considered relevant or necessary as a basis for our opinions set forth in this letter. In such review, we have assumed the accuracy and
completeness of all agreements, documents, records, certificates and other materials submitted to us, the conformity with the originals of all such materials submitted to us as copies (whether or not certified and including facsimiles), the
authenticity of the originals of such materials and all materials submitted to us as originals, the genuineness of all signatures and the legal capacity of all natural persons.
On the basis of the assumptions and subject to the qualifications and limitations set forth herein, we are of the opinion that the Shares have been duly
authorized and validly issued and are fully paid and nonassessable.
Our opinion set forth in this letter is limited to the General Corporation Law of the
State of Delaware, as in effect on the date hereof.
We hereby consent to the filing of this letter as Exhibit 5.1 to the Company’s Current Report
on Form 8-K filed by the Company with the Commission on the date hereof and the incorporation thereof in the Registration Statement and to the use of our name under the caption “Legal Matters” in
the Prospectus. In giving this consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.
Very truly yours,
/s/ Pillsbury Winthrop Shaw Pittman LLP
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