STOCK TITAN

Tenable (TENB) Co-CEO nets shares after RSU tax withholding

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

Tenable Holdings, Inc. Co-Chief Executive Officer Mark C. Thurmond reported routine equity compensation activity. On May 22, 2026, he exercised or converted awards into a total of 25,369 shares of Common Stock tied to Restricted Stock Units and Performance Restricted Stock Units. In connection with these vestings, 12,268 shares were withheld by the company at $25.45 per share to satisfy income tax obligations, and the filing notes these withholdings do not represent sales into the market. Following these transactions, Thurmond directly holds 170,249 shares of Tenable common stock.

Positive

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Insider Thurmond Mark C.
Role Co-Chief Executive Officer
Type Security Shares Price Value
Exercise Performance Restricted Stock Units 1,162 $0.00 --
Exercise Performance Restricted Stock Units 2,267 $0.00 --
Exercise Performance Restricted Stock Units 6,095 $0.00 --
Exercise Restricted Stock Units 3,713 $0.00 --
Exercise Restricted Stock Units 7,764 $0.00 --
Exercise Restricted Stock Units 4,368 $0.00 --
Exercise Common Stock 1,162 $0.00 --
Tax Withholding Common Stock 562 $25.45 $14K
Exercise Common Stock 2,267 $0.00 --
Tax Withholding Common Stock 1,097 $25.45 $28K
Exercise Common Stock 6,095 $0.00 --
Tax Withholding Common Stock 2,947 $25.45 $75K
Exercise Common Stock 3,713 $0.00 --
Tax Withholding Common Stock 1,796 $25.45 $46K
Exercise Common Stock 7,764 $0.00 --
Tax Withholding Common Stock 3,754 $25.45 $96K
Exercise Common Stock 4,368 $0.00 --
Tax Withholding Common Stock 2,112 $25.45 $54K
Holdings After Transaction: Performance Restricted Stock Units — 3,492 shares (Direct, null); Restricted Stock Units — 11,139 shares (Direct, null); Common Stock — 170,249 shares (Direct, null)
Footnotes (1)
  1. 820 shares were acquired under the Issuer's Employee Stock Purchase Plan in transactions that were exempt under both Rule 16b-3(d) and Rule 16b-3(c). 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 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. 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. 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 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. 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. 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.
RSU/PRSU shares exercised 25,369 shares Common Stock from RSU and PRSU exercises on May 22, 2026
Shares withheld for taxes 12,268 shares Withheld by issuer at $25.45 per share for tax obligations
Withholding reference price $25.45 per share Price used for tax-withholding share value on May 22, 2026
Common shares held after transactions 170,249 shares Direct Tenable common stock ownership following May 22, 2026 activity
Exercise transactions 6 transactions, 25,369 shares Derivative exercises/conversions (code M) summarized in filing
Tax-withholding transactions 6 transactions, 12,268 shares Tax-withholding dispositions (code F) summarized in filing
ESPP shares acquired 820 shares Acquired under Employee Stock Purchase Plan, exempt under Rule 16b-3
Restricted Stock Units financial
"Restricted Stock Units ("RSUs") and does not represent a sale."
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.
Performance Restricted Stock Units financial
"the 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.
Employee Stock Purchase Plan financial
"shares were acquired under the Issuer's Employee Stock Purchase Plan"
An employee stock purchase plan is a company program that lets workers buy shares through small payroll deductions, often at a discount to the market price and after a set offering period. Think of it like a workplace savings plan that turns into ownership: it encourages employees to share in the company’s success and can create predictable buying or selling of stock that investors watch because it affects supply, demand and employee incentives.
Rule 16b-3 regulatory
"exempt under both Rule 16b-3(d) and Rule 16b-3(c)."
Rule 16b-3 is a Securities and Exchange Commission regulation that exempts certain routine, pre-approved transactions by company insiders from automatic liability for short-term trading profits. It acts like a safe harbor: if an insider follows a formal plan or the board approves specific transactions in advance, profits from buying and selling company stock within six months are not automatically reclaimed. Investors care because the rule clarifies when insider trades are permissible and reduces uncertainty about potential clawbacks.
income tax withholding financial
"withheld by the issuer to satisfy its income tax withholding and remittance obligations"
SEC Form 4
FORM 4UNITED 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)
XDirector10% Owner
XOfficer (give title below)Other (specify below)
Co-Chief Executive Officer
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/22/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm 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)
CodeVAmount(A) or (D)Price
Common Stock05/22/2026M1,162A$0170,249(1)D
Common Stock05/22/2026F562(2)D$25.45169,687D
Common Stock05/22/2026M2,267A$0171,954D
Common Stock05/22/2026F1,097(2)D$25.45170,857D
Common Stock05/22/2026M6,095A$0176,952D
Common Stock05/22/2026F2,947(2)D$25.45174,005D
Common Stock05/22/2026M3,713A$0177,718D
Common Stock05/22/2026F1,796(2)D$25.45175,922D
Common Stock05/22/2026M7,764A$0183,686D
Common Stock05/22/2026F3,754(2)D$25.45179,932D
Common Stock05/22/2026M4,368A$0184,300D
Common Stock05/22/2026F2,112(2)D$25.45182,188D
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Performance Restricted Stock Units(3)05/22/2026M1,162 (4) (4)Common Stock1,162$03,492D
Performance Restricted Stock Units(3)05/22/2026M2,267 (5) (5)Common Stock2,267$015,873D
Performance Restricted Stock Units(3)05/22/2026M6,095 (6) (6)Common Stock6,095$067,052D
Restricted Stock Units(3)05/22/2026M3,713 (7) (7)Common Stock3,713$011,139D
Restricted Stock Units(3)05/22/2026M7,764 (8) (8)Common Stock7,764$085,408D
Restricted Stock Units(3)05/22/2026M4,368 (9) (9)Common Stock4,368$030,576D
Explanation of Responses:
1. 820 shares were acquired under the Issuer's Employee Stock Purchase Plan in transactions that were exempt under both Rule 16b-3(d) and Rule 16b-3(c).
2. 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.
3. Each RSU represents a contingent right to receive one share of Issuer common stock.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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-Fact05/26/2026
** Signature of Reporting PersonDate
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 transactions did Tenable (TENB) Co-CEO Mark Thurmond report?

Mark Thurmond reported routine equity compensation activity, exercising or converting awards into 25,369 shares of Tenable common stock. The company withheld 12,268 of those shares to cover income taxes, and the filing specifies these withholdings do not represent market sales.

How many Tenable (TENB) shares does Mark Thurmond hold after these Form 4 transactions?

After the reported transactions, Mark Thurmond directly holds 170,249 shares of Tenable common stock. This balance reflects net equity compensation activity on May 22, 2026, including award vesting and share withholding for income tax obligations noted in the filing.

Were any of Mark Thurmond’s Tenable (TENB) Form 4 transactions open-market sales?

The filing indicates no open-market sales. Shares with transaction code “F” were withheld by Tenable to satisfy income tax obligations at $25.45 per share, and a footnote clarifies these withholdings are not sales into the market.

What role did Restricted Stock Units play in this Tenable (TENB) Form 4?

Restricted Stock Units and Performance Restricted Stock Units converted into 25,369 Tenable common shares on May 22, 2026. Footnotes explain that each RSU or PRSU represents a contingent right to one share, with vesting schedules tied to service and previously certified performance.

Were any Tenable (TENB) shares acquired under an Employee Stock Purchase Plan?

Footnotes note that 820 Tenable shares were acquired under the company’s Employee Stock Purchase Plan in transactions exempt under Rule 16b-3(d) and Rule 16b-3(c). These acquisitions are separate from the RSU and PRSU-related transactions detailed in the Form 4.