Tenable (TENB) co-CEO reports 341,847 RSU grant and PRSU vesting

Rhea-AI Filing Summary

Tenable Holdings director and Co-Chief Executive Officer Mark C. Thurmond reported multiple equity transactions. He received a grant of 341,847 Restricted Stock Units (RSUs) at no cost, each representing one share of common stock, with 25% vesting on February 22, 2027 and the rest vesting quarterly over three years.

On February 25, 2026, 24,381 Performance RSUs were certified at a 97.2% payout and converted into 24,381 shares of common stock, with 25% vesting immediately and the remainder vesting in equal quarterly installments over three years. The filing also shows 11,789 shares of common stock withheld at $19.00 per share to satisfy tax obligations in connection with RSU settlement, which the footnotes state does not represent a sale.

Insider Trade Summary

24,381 shares exercised/converted

Mixed 4 txns

Insider Thurmond Mark C.

Role Co-Chief Executive Officer

Type	Security	Shares	Price	Value
Grant/Award	Restricted Stock Units	341,847	$0.00	--
Exercise	Performance Restricted Stock Units	24,381	$0.00	--
Exercise	Common Stock	24,381	$0.00	--
Tax Withholding	Common Stock	11,789	$19.00	$224K

Holdings After Transaction: Restricted Stock Units — 341,847 shares (Direct); Performance Restricted Stock Units — 73,147 shares (Direct); Common Stock — 180,056 shares (Direct)

Footnotes (1)

1. Represents the number of shares of Common Stock that have been withheld by the issuer to satisfy its income tax withholding and remittance obligations in connection with the net settlement of the Restricted Stock Units ("RSUs") and does not represent a sale. Each RSU represents a contingent right to receive one share of Issuer common stock. On February 25, 2026, the Compensation Committee of the Issuer's Board of Directors certified the achievement of the Performance Restricted Stock Units (PRSUs) granted on February 21, 2025 and determined a 97.2% payout for the measurement period based on the Issuer's fiscal year 2025 criteria. 25% of the shares underlying the PRSUs vested on February 25, 2026, with the remainder vesting in equal quarterly installments over 3 years, subject to the Reporting Person's continuous service with the Issuer as of the applicable vesting date, and subject to accelerated vesting in specified circumstances. 25% of the shares underlying the RSUs vest on February 22, 2027, with the remainder vesting in equal quarterly installments over 3 years, subject to the Reporting Person's continuous service with the Issuer as of the applicable vesting date, and subject to accelerated vesting in specified circumstances.

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

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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^*

Thurmond Mark C.

(Last) (First) (Middle)

C/O TENABLE HOLDINGS, INC.

6100 MERRIWEATHER DRIVE

(Street)

COLUMBIA MD 21044

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Tenable Holdings, Inc. [ TENB ]

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

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Co-Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/25/2026

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

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

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

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	02/25/2026		M		24,381	A	$0	180,056	D
Common Stock	02/25/2026		F		11,789(1)	D	$19	168,267	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
Performance Restricted Stock Units	(2)	02/25/2026		M			24,381	(3)	(3)	Common Stock	24,381	$0	73,147	D
Restricted Stock Units	(2)	02/26/2026		A		341,847		(4)	(4)	Common Stock	341,847	$0	341,847	D

Explanation of Responses:

1. Represents the number of shares of Common Stock that have been withheld by the issuer to satisfy its income tax withholding and remittance obligations in connection with the net settlement of the Restricted Stock Units ("RSUs") and does not represent a sale.

2. Each RSU represents a contingent right to receive one share of Issuer common stock.

3. On February 25, 2026, the Compensation Committee of the Issuer's Board of Directors certified the achievement of the Performance Restricted Stock Units (PRSUs) granted on February 21, 2025 and determined a 97.2% payout for the measurement period based on the Issuer's fiscal year 2025 criteria. 25% of the shares underlying the PRSUs vested on February 25, 2026, with the remainder vesting in equal quarterly installments over 3 years, subject to the Reporting Person's continuous service with the Issuer as of the applicable vesting date, and subject to accelerated vesting in specified circumstances.

4. 25% of the shares underlying the RSUs vest on February 22, 2027, with the remainder vesting in equal quarterly installments over 3 years, subject to the Reporting Person's continuous service with the Issuer as of the applicable vesting date, and subject to accelerated vesting in specified circumstances.

Remarks:

	/s/ David Bartholomew, Attorney-in-Fact	02/27/2026
	** 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.
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FAQ

What insider equity awards were reported for TENB’s Mark C. Thurmond?

Mark C. Thurmond reported a grant of 341,847 Restricted Stock Units and activity in 24,381 Performance RSUs. Each RSU and PRSU represents a contingent right to one Tenable common share, with vesting tied to continued service and performance certification.

How do the new RSUs for TENB’s co-CEO vest over time?

For the 341,847 RSUs, 25% of the shares vest on February 22, 2027. The remaining RSUs vest in equal quarterly installments over three years, subject to Mark C. Thurmond’s continued service and specified accelerated vesting conditions.

What happened with Tenable’s Performance RSUs in this Form 4?

On February 25, 2026, the compensation committee certified Performance RSUs granted in February 2025 at a 97.2% payout. 25% of the underlying shares vested that day, with the rest vesting in equal quarterly installments over three years, contingent on continued service.

Did Mark C. Thurmond sell Tenable (TENB) shares in this filing?

The filing shows 11,789 common shares with transaction code F at $19.00 per share. A footnote explains these shares were withheld by Tenable to cover tax obligations from RSU settlement and explicitly states this does not represent a sale transaction.

How many Tenable common shares does Mark C. Thurmond hold after these transactions?

After the reported transactions, Mark C. Thurmond directly holds 168,267 shares of Tenable common stock. He also has 341,847 RSUs and 73,147 Performance RSUs outstanding, each representing a contingent right to receive one additional Tenable common share upon vesting.

What role does performance play in Tenable’s PRSU payout for Mark C. Thurmond?

The Performance RSUs granted on February 21, 2025 were subject to fiscal 2025 performance criteria. On February 25, 2026, Tenable’s compensation committee certified results and determined a 97.2% payout, which drove how many PRSU-linked shares vested and will vest going forward.