A10 Networks, Inc. — Director's Dealing 2021

Nov 4, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: A10 Networks, Inc. (ATEN)
CIK: 0001580808
Period of Report: 2021-11-01

Reporting Person: Singer Eric (Director)
Reporting Person: VIEX Opportunities Fund, LP Series One (See Explanation of Responses)
Reporting Person: VIEX Opportunities Fund, LP - Series Two (See Explanation of Responses)
Reporting Person: VIEX Special Opportunities Fund II, LP (See Explanation of Responses)
Reporting Person: VIEX Special Opportunities Fund III, LP (See Explanation of Responses)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-11-01	Common Stock, par value $0.00001	S	346000	$16.0076	Disposed	1119781	Indirect
2021-11-02	Common Stock, par value $0.00001	S	200050	$15.3412	Disposed	919731	Indirect
2021-11-03	Common Stock, par value $0.00001	S	274190	$15.7042	Disposed	645541	Indirect
2021-11-01	Common Stock, par value $0.00001	S	122000	$16.0076	Disposed	360877	Indirect
2021-11-02	Common Stock, par value $0.00001	S	75019	$15.3412	Disposed	285858	Indirect
2021-11-03	Common Stock, par value $0.00001	S	102822	$15.7042	Disposed	183036	Indirect
2021-11-01	Common Stock, par value $0.00001	S	550000	$16.0076	Disposed	4705022	Indirect
2021-11-01	Common Stock, par value $0.00001	J	2607705	—	Disposed	2097317	Indirect
2021-11-02	Common Stock, par value $0.00001	S	350087	$15.3412	Disposed	1747230	Indirect
2021-11-03	Common Stock, par value $0.00001	S	479832	$15.7042	Disposed	1267398	Indirect
2021-11-01	Common Stock, par value $0.00001	J	487416	—	Disposed	0	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock, par value $0.00001	73139	Direct

Footnotes

F1: This Form 4 is filed jointly by VIEX Opportunities Fund, LP - Series One ("Series One"), a series of VIEX Opportunities Fund, LP, VIEX Opportunities Fund, LP - Series Two ("Series Two"), a series of VIEX Opportunities Fund, LP, VIEX Special Opportunities Fund II, LP ("VSO II"), VIEX Special Opportunities Fund III, LP ("VSO III"), VIEX GP, LLC ("VIEX GP"), VIEX Special Opportunities GP II, LLC ("VSO GP II"), VIEX Special Opportunities GP III, LLC ("VSO GP III"), VIEX Capital Advisors, LLC ("VIEX Capital"), and Eric Singer (collectively, the "Reporting Persons").

F2: Each Reporting Person disclaims beneficial ownership of the securities of the Issuer reported herein except to the extent of his or its pecuniary interest therein, and this report shall not be deemed to be an admission that any Reporting Person is the beneficial owner of such securities for purposes of Section 16 or any other purpose.

F3: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.00 to $18.58 per share. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote 3.

F4: Securities of the Issuer beneficially owned directly by Series One. VIEX GP, as the general partner of Series One, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series One. VIEX Capital, as the investment manager of Series One, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series One. Mr. Singer, as the managing member of each of VIEX GP and VIEX Capital, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series One.

F5: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.20 to $15.525 per share. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote 5.

F6: The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.40 to $16.06 per share. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote 6.

F7: Securities of the Issuer beneficially owned directly by Series Two. VIEX GP, as the general partner of Series Two, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series Two. VIEX Capital, as the investment manager of Series Two, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series Two. Mr. Singer, as the managing member of each of VIEX GP and VIEX Capital, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by Series Two.

F8: Securities of the Issuer beneficially owned directly by VSO II. VSO GP II, as the general partner of VSO II, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO II. VIEX Capital, as the investment manager of VSO II, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO II. Mr. Singer, as the managing member of each of VSO GP II and VIEX Capital, may be deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO II.

F9: Represents a pro-rata distribution of shares to limited partners by VSO II.

F10: Represents a pro-rata distribution of shares to limited partners by VSO III.

F11: Securities of the Issuer that were beneficially owned directly by VSO III. VSO GP III, as the general partner of VSO III, may have been deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO III. VIEX Capital, as the investment manager of VSO III, may have been deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO III. Mr. Singer, as the managing member of each of VSO GP III and VIEX Capital, may have been deemed the beneficial owner of the securities of the Issuer beneficially owned by VSO III.