A10 Networks (ATEN) CFO amends Form 4 for RSU tax-withholding correction

Rhea-AI Filing Summary

A10 Networks, Inc. Chief Financial Officer Michelle Elizabeth Caron filed an amended insider report to correct a prior tax-withholding entry. The amendment updates the number of shares withheld and the price used for shares retained to cover taxes on a performance-based RSU grant that vested on May 14, 2026.

The corrected record shows 760 shares of common stock were withheld on a non-discretionary basis at $28.03 per share for tax purposes. After this correction, Caron directly owns 35,614 shares of A10 Networks common stock as of May 15, 2026.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Caron Michelle Elizabeth

Role Chief Financial Officer

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock	760	$28.03	$21K

Holdings After Transaction: Common Stock — 35,614 shares (Direct, null)

Footnotes (1)

1. This amendment to the original Form 4 filed on May 15, 2026 is being filed to correct the number of shares withheld, on a non-discretionary basis, for tax purposes related to a February 12, 2026 perfomance-based restricted stock unit grant that vested on May 14, 2026. This amendment to the original Form 4 filed on May 15, 2026 is also being filed to correc the price reported on Column 4 of Table I in connection with the shares withheld, on a non-discretionary basis, for tax purposes related to a February 12, 2026 performance-based restricted stock unit grant that vested on May 14, 2026. The total number of shares reported on Column 5 of Table I of this amendment is the total owned by the reporting person as of May 15, 20206, which reflects the corrected number of shares withheld.

Key Figures

Shares withheld for taxes: 760 shares Withholding share price: $28.03 per share Shares owned after transaction: 35,614 shares +3 more

6 metrics

Shares withheld for taxes 760 shares Non-discretionary tax withholding on May 15, 2026

Withholding share price $28.03 per share Price reported for withheld common stock

Shares owned after transaction 35,614 shares Direct common stock ownership as of May 15, 2026

Tax-withholding transactions 1 transaction, 760 shares Summary of F-code dispositions in this filing

RSU grant date February 12, 2026 Performance-based restricted stock unit grant

RSU vesting date May 14, 2026 Vesting that triggered tax withholding

Key Terms

performance-based restricted stock unit, tax-withholding disposition, Form 4 amendment, non-discretionary basis

4 terms

performance-based restricted stock unit financial

"related to a February 12, 2026 perfomance-based restricted stock unit grant that vested"

A performance-based restricted stock unit is a promise of company shares given to an employee that only becomes actual stock if specific performance targets are met and any required time at the company is completed. For investors, these awards matter because they can dilute existing shares when earned and signal management’s confidence or the company’s expected future performance, much like a bonus cheque that only clears when pre-set goals are reached.

tax-withholding disposition financial

"transaction_action": "tax-withholding disposition""

A tax-withholding disposition is an event or transaction—such as selling or transferring securities, exercising options, or receiving compensation—that triggers a requirement to hold back part of the payment and remit it to tax authorities. It matters to investors because it reduces the cash they receive immediately and can change the timing and amount of taxable income, like a cashier taking a portion of your sale proceeds to pay taxes before you get the rest.

Form 4 amendment regulatory

"This amendment to the original Form 4 filed on May 15, 2026 is being filed"

non-discretionary basis financial

"shares withheld, on a non-discretionary basis, for tax purposes"

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Caron Michelle Elizabeth

(Last) (First) (Middle)

2300 ORCHARD PARKWAY

(Street)

SAN JOSE CALIFORNIA 95131

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
A10 Networks, Inc. [ ATEN ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/15/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)
05/15/2026

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/15/2026		F		760(1)	D	$28.03(2)	35,614(3)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. This amendment to the original Form 4 filed on May 15, 2026 is being filed to correct the number of shares withheld, on a non-discretionary basis, for tax purposes related to a February 12, 2026 perfomance-based restricted stock unit grant that vested on May 14, 2026.

2. This amendment to the original Form 4 filed on May 15, 2026 is also being filed to correc the price reported on Column 4 of Table I in connection with the shares withheld, on a non-discretionary basis, for tax purposes related to a February 12, 2026 performance-based restricted stock unit grant that vested on May 14, 2026.

3. The total number of shares reported on Column 5 of Table I of this amendment is the total owned by the reporting person as of May 15, 20206, which reflects the corrected number of shares withheld.

Remarks:

	/s/ Jill Osato, as Attorney-in-Fact	05/15/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did A10 Networks (ATEN) report in this Form 4/A amendment?

A10 Networks reported an amended insider transaction for its CFO, correcting a prior tax-withholding entry. The filing now shows 760 common shares were withheld on a non-discretionary basis to cover taxes tied to a performance-based RSU grant that recently vested.

How many A10 Networks (ATEN) shares were withheld for taxes in the corrected Form 4/A?

The corrected Form 4/A states that 760 A10 Networks common shares were withheld for tax purposes. These shares relate to a February 12, 2026 performance-based restricted stock unit grant that vested on May 14, 2026, and were withheld on a non-discretionary basis.

At what price were the withheld A10 Networks (ATEN) shares reported in the amended Form 4/A?

The amended Form 4/A reports the withheld A10 Networks shares at $28.03 per share. This corrects the price previously shown in Column 4 and aligns with the non-discretionary tax withholding tied to the vesting of a performance-based restricted stock unit grant.

How many A10 Networks (ATEN) shares does the CFO own after this amended filing?

After the correction, the CFO is reported as directly owning 35,614 A10 Networks common shares. This total, shown in Column 5, reflects the adjusted number of shares withheld for taxes in connection with the May 14, 2026 vesting event.

What equity award triggered the tax-withholding correction in A10 Networks (ATEN) Form 4/A?

The correction relates to a performance-based restricted stock unit grant dated February 12, 2026. That RSU award vested on May 14, 2026, and the company withheld 760 shares on a non-discretionary basis to satisfy tax obligations associated with the vesting event.