Tenable co-CEO exercises 25K units, withholds tax

Tenable Holdings, Inc. (TENB) reported insider equity activity by Co-Chief Executive Officer Mark C. Thurmond.

Rhea-AI Filing Summary

Tenable Holdings, Inc. (TENB) reported insider equity activity by Co-Chief Executive Officer Mark C. Thurmond. On August 24, 2026, multiple tranches of Performance Restricted Stock Units (PRSUs) and Restricted Stock Units (RSUs) converted into common stock as they vested, reflecting previously granted equity awards.

The filing shows exercises or conversions covering 25,369 shares12,268 shares$33.9493.9%96.4%97.2%

Insider Trade Summary

25,369 shares exercised/converted

Exercise 18 txns

Insider Thurmond Mark C.

Role Co-Chief Executive Officer

Type	Security	Shares	Price	Value
Exercise	Performance Restricted Stock Units F2, F3	1,162	$0.00	$0.00
Exercise	Performance Restricted Stock Units F2, F4	2,267	$0.00	$0.00
Exercise	Performance Restricted Stock Units F2, F5	6,095	$0.00	$0.00
Exercise	Restricted Stock Units F2, F6	3,713	$0.00	$0.00
Exercise	Restricted Stock Units F2, F7	7,764	$0.00	$0.00
Exercise	Restricted Stock Units F2, F8	4,368	$0.00	$0.00
Exercise	Common Stock	1,162	$0.00	$0.00
Tax Withholding	Common Stock F1	562	$33.94	$19K
Exercise	Common Stock	2,267	$0.00	$0.00
Tax Withholding	Common Stock F1	1,097	$33.94	$37K
Exercise	Common Stock	6,095	$0.00	$0.00
Tax Withholding	Common Stock F1	2,947	$33.94	$100K
Exercise	Common Stock	3,713	$0.00	$0.00
Tax Withholding	Common Stock F1	1,796	$33.94	$61K
Exercise	Common Stock	7,764	$0.00	$0.00
Tax Withholding	Common Stock F1	3,754	$33.94	$127K
Exercise	Common Stock	4,368	$0.00	$0.00
Tax Withholding	Common Stock F1	2,112	$33.94	$72K

Holdings After Transaction: Performance Restricted Stock Units — 76,893 contracts (Direct); Restricted Stock Units — 111,278 contracts (Direct); Common Stock — 195,289 shares (Direct)

Footnotes (8)

1. F1. 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. F2. Each restricted stock unit ("RSU") represents a contingent right to receive one share of Issuer common stock.
3. F3. On February 21, 2024, the Compensation Committee of the Issuer's Board of Directors certified the achievement of the Performance Restricted Stock Units (PRSUs) granted on February 22, 2023 and determined a 93.9% payout for the measurement period based on the Issuer's fiscal year 2023 criteria. 25% of the shares underlying the PRSUs vested on February 22, 2024, 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. F4. On February 13, 2025, the Compensation Committee of the Issuer's Board of Directors certified the achievement of the Performance Restricted Stock Units (PRSUs) granted on February 22, 2024 and determined a 96.4% payout for the measurement period based on the Issuer's fiscal year 2024 criteria. 25% of the shares underlying the PRSUs vested on February 22, 2025, 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.
5. F5. 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.
6. F6. 25% of the shares underlying the RSUs vested on February 22, 2024, 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.
7. F7. 25% of the shares underlying the RSUs vested on August 22, 2025, 25% on February 22, 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.
8. F8. 25% of the shares underlying the RSUs vested on February 22, 2025, 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.

Key Figures

Derivative exercises: 25,369 shares Tax-withholding shares: 12,268 shares Withholding price: $33.94 per share +3 more

6 metrics

Derivative exercises 25,369 shares Total shares underlying PRSUs and RSUs exercised or converted (code M) reported in the transaction summary

Tax-withholding shares 12,268 shares Shares withheld to satisfy income tax obligations on RSU/PRSU settlements (code F) in the transaction summary

Withholding price $33.94 per share Price used for common stock withheld for tax purposes in all code F transactions, as stated in the filing

PRSU payout (2023 grant) 93.9% Payout level for PRSUs granted on February 22, 2023, based on Tenable’s fiscal year 2023 performance criteria

PRSU payout (2024 grant) 96.4% Payout level for PRSUs granted on February 22, 2024, based on fiscal year 2024 performance criteria

PRSU payout (2025 grant) 97.2% Payout level for PRSUs granted on February 21, 2025, based on fiscal year 2025 performance criteria

Key Terms

Performance Restricted Stock Units, Restricted Stock Units, net settlement, income tax withholding, +1 more

5 terms

Performance Restricted Stock Units financial

"Performance Restricted Stock Units (PRSUs) granted on February 22, 2023"

Performance restricted stock units (PRSUs) are promises to deliver company shares to employees or executives only if the business meets specific performance targets and any time-based holding rules. Think of them as a bonus that converts into stock only after set goals are reached, so investors watch PRSUs for two reasons: they can dilute existing shares if paid out, and they signal how closely management’s pay is tied to company performance.

Restricted Stock Units financial

"Represents the number of shares of Common Stock that have been withheld"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

net settlement financial

"obligations in connection with the net settlement of the Restricted Stock Units"

income tax withholding financial

"withheld by the issuer to satisfy its income tax withholding and remittance"

accelerated vesting financial

"subject to accelerated vesting in specified circumstances"

A contract feature that makes stock awards, options, or restricted shares become owned or exercisable earlier than the original schedule. It shortens or cancels the waiting period so recipients can sell, transfer, or exercise their equity sooner — think of a timed lock that is unlocked ahead of schedule. It matters to investors because it changes when shares enter the market, who controls them, and how much dilution or ownership concentration happens.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transactions did TENB Co-CEO Mark C. Thurmond report on August 24, 2026?

Mark C. Thurmond reported the exercise or conversion25,369 sharestax-withholding transactions in which 12,268 shares

Were any of Mark C. Thurmond’s TENB shares sold on the open market in this Form 4?

The filing describes withholding of 12,268 shares$33.94 per sharedo not represent a sale," and there are no reported open-market purchases or sales.

How many Tenable (TENB) shares were involved in equity award exercises in this Form 4?

The transaction summary reports 25,369 sharesAugust 24, 2026

What tax-withholding activity is disclosed for TENB in this insider filing?

The filing shows 12,268 shares$33.94 per share

What PRSU performance payouts are disclosed for Tenable (TENB) in the footnotes?

Footnotes state PRSU achievement levels of 93.9%96.4%97.2%

How do Mark C. Thurmond’s TENB RSUs and PRSUs vest according to this filing?

For the disclosed RSUs and PRSUs, footnotes state that 25%equal quarterly installments over three years, subject to continued service and certain accelerated-vesting conditions.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/25/2026 - 04:03 PM EDT Accepted by SEC EDGAR 08/25/2026 - 04:03 PM EDT Learn about SEC filing dates

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^*

Thurmond Mark C.

(Last) (First) (Middle)

C/O TENABLE HOLDINGS, INC.

6100 MERRIWEATHER DRIVE

(Street)

COLUMBIA MARYLAND 21044

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
08/24/2026

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)

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	08/24/2026		M		1,162	A	$0	183,350	D
Common Stock	08/24/2026		F		562(1)	D	$33.94	182,788	D
Common Stock	08/24/2026		M		2,267	A	$0	185,055	D
Common Stock	08/24/2026		F		1,097(1)	D	$33.94	183,958	D
Common Stock	08/24/2026		M		6,095	A	$0	190,053	D
Common Stock	08/24/2026		F		2,947(1)	D	$33.94	187,106	D
Common Stock	08/24/2026		M		3,713	A	$0	190,819	D
Common Stock	08/24/2026		F		1,796(1)	D	$33.94	189,023	D
Common Stock	08/24/2026		M		7,764	A	$0	196,787	D
Common Stock	08/24/2026		F		3,754(1)	D	$33.94	193,033	D
Common Stock	08/24/2026		M		4,368	A	$0	197,401	D
Common Stock	08/24/2026		F		2,112(1)	D	$33.94	195,289	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)	08/24/2026		M			1,162	(3)	(3)	Common Stock	1,162	$0	2,330	D
Performance Restricted Stock Units	(2)	08/24/2026		M			2,267	(4)	(4)	Common Stock	2,267	$0	13,606	D
Performance Restricted Stock Units	(2)	08/24/2026		M			6,095	(5)	(5)	Common Stock	6,095	$0	60,957	D
Restricted Stock Units	(2)	08/24/2026		M			3,713	(6)	(6)	Common Stock	3,713	$0	7,426	D
Restricted Stock Units	(2)	08/24/2026		M			7,764	(7)	(7)	Common Stock	7,764	$0	77,644	D
Restricted Stock Units	(2)	08/24/2026		M			4,368	(8)	(8)	Common Stock	4,368	$0	26,208	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 restricted stock unit ("RSU") represents a contingent right to receive one share of Issuer common stock.

3. On February 21, 2024, the Compensation Committee of the Issuer's Board of Directors certified the achievement of the Performance Restricted Stock Units (PRSUs) granted on February 22, 2023 and determined a 93.9% payout for the measurement period based on the Issuer's fiscal year 2023 criteria. 25% of the shares underlying the PRSUs vested on February 22, 2024, 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. On February 13, 2025, the Compensation Committee of the Issuer's Board of Directors certified the achievement of the Performance Restricted Stock Units (PRSUs) granted on February 22, 2024 and determined a 96.4% payout for the measurement period based on the Issuer's fiscal year 2024 criteria. 25% of the shares underlying the PRSUs vested on February 22, 2025, 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.

5. 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.

6. 25% of the shares underlying the RSUs vested on February 22, 2024, 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.

7. 25% of the shares underlying the RSUs vested on August 22, 2025, 25% on February 22, 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.

8. 25% of the shares underlying the RSUs vested on February 22, 2025, 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	08/25/2026
	** 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)