TENB Insider Filing: RSU/PRSU Vestings Boost CEO Holdings; 28,500 Shares Sold at $30.25

Rhea-AI Filing Summary

Tenable Holdings insider report: Mark C. Thurmond, Co-Chief Executive Officer and director, filed a Form 4 disclosing multiple automatic acquisitions and a single taxable sale. On 08/22/2025 and 08/25/2025 he was credited with a series of vested RSUs and PRSUs totaling multiple grant-year vesting events, increasing his direct beneficial holdings from 73,889 shares to 107,542 shares after the 08/25/2025 transactions. On 08/25/2025 he recorded a sell-to-cover disposition of 28,500 shares at $30.25 per share to satisfy tax-withholding obligations related to RSU vesting. All acquisitions show $0 purchase price (vesting) and ownership is reported as direct.

Insights

Corporate Governance Expert

TL;DR: CEO disclosed multiple RSU/PRSU vestings and an automatic sell-to-cover of 28,500 shares to cover taxes; holdings rose materially.

The Form 4 reflects routine equity compensation settlement and tax-related disposition rather than open-market discretionary trading. Several performance and restricted stock units vested or were credited on 08/22/2025 and 08/25/2025, increasing the reporting person's direct holdings to 107,542 shares after the August transactions. The single sale of 28,500 shares at $30.25 is explicitly described as an automatic sell-to-cover for tax withholding. From a governance standpoint, these are typical executive compensation mechanics and indicate retention via equity vesting, not an active liquidation decision.

Securities Analyst

TL;DR: Insider holdings rose through vesting; one tax-driven sale executed at $30.25 for 28,500 shares—no open-market discretionary sale noted.

The disclosure details multiple vesting events for RSUs and PRSUs across prior grant cycles with specific payout certifications cited (e.g., 93.9%, 96.4%, 106% for various measurement periods). Vesting-driven issuances are recorded at $0 acquisition price as they represent granted compensation. The sell-to-cover transaction is quantified and priced, allowing precise calculation of shares retained versus sold for withholding. For investors assessing insider activity, this filing documents compensation realization rather than voluntary portfolio reallocation.

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
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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)
08/22/2025

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	08/22/2025		M		1,162	A	$0	73,889	D
Common Stock	08/22/2025		M		2,267	A	$0	76,156	D
Common Stock	08/22/2025		M		3,713	A	$0	79,869	D
Common Stock	08/22/2025		M		46,585	A	$0	126,454	D
Common Stock	08/22/2025		M		4,368	A	$0	130,822	D
Common Stock	08/25/2025		S(1)		28,500	D	$30.25	102,322	D
Common Stock	08/25/2025		M		1,363	A	$0	103,685	D
Common Stock	08/25/2025		M		3,857	A	$0	107,542	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)	08/22/2025		M			1,162	(3)	(3)	Common Stock	1,162	$0	6,978	D
Performance Restricted Stock Units	(2)	08/22/2025		M			2,267	(4)	(4)	Common Stock	2,267	$0	22,674	D
Restricted Stock Units	(2)	08/22/2025		M			3,713	(5)	(5)	Common Stock	3,713	$0	22,278	D
Restricted Stock Units	(2)	08/22/2025		M			46,585	(6)	(6)	Common Stock	46,585	$0	139,758	D
Restricted Stock Units	(2)	08/22/2025		M			4,368	(7)	(7)	Common Stock	4,368	$0	43,680	D
Performance Restricted Stock Units	(2)	08/25/2025		M			1,363	(8)	(8)	Common Stock	1,363	$0	2,728	D
Restricted Stock Units	(2)	08/25/2025		M			3,857	(9)	(9)	Common Stock	3,857	$0	7,714	D

Explanation of Responses:

1. The sale reported on this Form 4 represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. The sale occurred automatically to satisfy the tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary trade by the Reporting Person.

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. 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.

6. 25% of the shares underlying the RSUs vested on August 22, 2025, then 25% of the remaining will vest 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.

7. 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.

8. On February 22, 2023, the Compensation Committee of the Issuer's Board of Directors certified the achievement of the Performance Restricted Stock Units (PRSUs) granted on February 23, 2022 and determined a 106% payout for the measurement period based on the Issuer's fiscal year 2022 criteria. 25% of the shares underlying the PRSUs vested on February 23, 2023, 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.

9. 25% of the shares underlying the RSUs vested on February 23, 2023, 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	08/26/2025
	** 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).
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FAQ

What insider activity did TENB CEO Mark Thurmond report on Form 4?

The Form 4 shows multiple RSU and PRSU vestings on 08/22/2025 and 08/25/2025 plus a sell-to-cover sale of 28,500 shares at $30.25 to satisfy tax withholding.

How many shares does Mark Thurmond beneficially own after the reported transactions?

After the 08/25/2025 transactions the filing reports total direct beneficial ownership of 107,542 shares.

Why were shares sold on 08/25/2025 according to the filing?

The filing states the sale of 28,500 shares was an automatic 'sell-to-cover' transaction to satisfy tax withholding obligations arising from RSU vesting.

Were the acquisitions purchases or vesting events?

All acquisitions are reported with a $0 price and are described as RSU/PRSU vesting events (equity compensation settlements), not open-market purchases.

Does the filing indicate whether these were discretionary trades by the CEO?

No; the filing specifies the sale was automatic to cover taxes and the other transactions are vesting-related—there is no indication of discretionary open-market trading.