Insider · CIK 0001651579
Mark C. Thurmond
cooofficerceodirector
Files at TENB (Tenable Holdings, Inc.). First filing Nov 20, 2024, latest Aug 27, 2025.
Mark C. Thurmond files SEC Form 4 as COO, CEO and director at TENB (Tenable Holdings, Inc.). Since Nov 20, 2024, Mark C. Thurmond has reported 0 open-market buys worth $0 and 9 open-market sells worth $1.6M, the latest filed on Aug 27, 2025.
A track record needs three past buys with six months of prices behind them; Mark C. Thurmond has 0, so none is measured yet.
The newest scored trade: sold $76k of TENB on Aug 26, 2025, filed Aug 27, 2025, scored 48 (moderate).
Track record
Not enough history
Fewer than three past buys with six months of prices.
Median 6-month excess
-
after past buys, n = 0
Hit rate
-
past buys that beat the index over 6 months
Open-market trades
0 / 9
$0 bought, $1.6M sold
Where the trades landed
Last year at the company this insider has traded most, with each buy and sell on the bar it happened.
TENB: Tenable Holdings, Inc.
TENBOct 9, 2026 · close 41.59
Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value. Click a marked bar to open the signal.Charts by TradingView Lightweight Charts™
Signals
This insider’s open-market buys and sells, scored.
| Score | Company | Value | Holdings | Price context | Filed |
|---|---|---|---|---|---|
| 48Moderate | Tenable Holdings, Inc. | $76k 2,541 shares | -2% | +3% from low-34% from high | |
| 53Moderate | Tenable Holdings, Inc. | $862k 28,500 shares | -22% | +5% from low-33% from high | |
| 49Moderate | Tenable Holdings, Inc. | $81k 2,483 shares | -3% | +7% from low-27% from high | |
| 37Weak | Tenable Holdings, Inc. | $178k 5,577 shares | -7% | +5% from low-28% from high | |
| 21Weak | Tenable Holdings, Inc. | $40k 939 shares | -2% | - | |
| 26Weak | Tenable Holdings, Inc. | $146k 3,423 shares | -8% | - | |
| 30Weak | Tenable Holdings, Inc. | $100k 2,343 shares | -6% | - | |
| 21Weak | Tenable Holdings, Inc. | $34k 823 shares | -2% | - | |
| 29Weak | Tenable Holdings, Inc. | $90k 2,209 shares | -6% | - |
Planned sales
Form 144 notices this insider filed before selling restricted or control stock, newest first.
| Filed | Company | Shares | Value | Sale date | Past 3 months |
|---|---|---|---|---|---|
| Aug 26, 2025 | TENB Tenable Holdings, Inc. | 2,541 0.00% of outstanding | $76k | Aug 26, 2025 | $943k |
| Aug 25, 2025 | TENB Tenable Holdings, Inc. | 28,500 0.02% of outstanding | $862k | Aug 25, 2025 | $81k |
| May 27, 2025 | TENB Tenable Holdings, Inc. | 2,483 0.00% of outstanding | $81k | May 27, 2025 | $407k |
| May 23, 2025 | TENB Tenable Holdings, Inc. | 5,577 0.00% of outstanding | $178k | May 23, 2025 | $553k |
| Feb 27, 2025 | TENB Tenable Holdings, Inc. | 5,984 0.01% of outstanding | $228k | Feb 27, 2025 | $418k |
| Feb 26, 2025 | TENB Tenable Holdings, Inc. | 4,878 0.00% of outstanding | $186k | Feb 26, 2025 | $378k |
| Feb 25, 2025 | TENB Tenable Holdings, Inc. | 3,606 0.00% of outstanding | $139k | Feb 25, 2025 | $339k |
| Feb 19, 2025 | TENB Tenable Holdings, Inc. | 1,341 0.00% of outstanding | $53k | Feb 19, 2025 | $410k |
| Nov 27, 2024 | TENB Tenable Holdings, Inc. | 939 0.00% of outstanding | $40k | Nov 27, 2024 | $408k |
| Nov 26, 2024 | TENB Tenable Holdings, Inc. | 886 0.00% of outstanding | $38k | Nov 26, 2024 | $404k |
| Nov 26, 2024 | TENB Tenable Holdings, Inc. | 2,537 0.00% of outstanding | $108k | Nov 26, 2024 | $404k |
| Nov 25, 2024 | TENB Tenable Holdings, Inc. | 2,343 0.00% of outstanding | $100k | Nov 25, 2024 | $303k |
| Nov 20, 2024 | TENB Tenable Holdings, Inc. | 823 0.00% of outstanding | $34k | Nov 20, 2024 | $496k |
| Nov 19, 2024 | TENB Tenable Holdings, Inc. | 2,209 0.00% of outstanding | $90k | Nov 19, 2024 | $407k |
Transactions
The newest 50 of 107 rows this insider has filed.
| Date | Company | Transaction | Shares | Price | Value | Holdings after | Filed |
|---|---|---|---|---|---|---|---|
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +1,162 | $0.00 | $0 | 170,249 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -562 | $25.45 | $14k | 169,687 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +2,267 | $0.00 | $0 | 171,954 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -1,097 | $25.45 | $28k | 170,857 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +6,095 | $0.00 | $0 | 176,952 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -2,947 | $25.45 | $75k | 174,005 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +3,713 | $0.00 | $0 | 177,718 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -1,796 | $25.45 | $46k | 175,922 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +7,764 | $0.00 | $0 | 183,686 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -3,754 | $25.45 | $96k | 179,932 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +4,368 | $0.00 | $0 | 184,300 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -2,112 | $25.45 | $54k | 182,188 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Performance Restricted Stock Unitsderivative | -1,162 | $0.00 | $0 | 3,492 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Performance Restricted Stock Unitsderivative | -2,267 | $0.00 | $0 | 15,873 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Performance Restricted Stock Unitsderivative | -6,095 | $0.00 | $0 | 67,052 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Restricted Stock Unitsderivative | -3,713 | $0.00 | $0 | 11,139 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Restricted Stock Unitsderivative | -7,764 | $0.00 | $0 | 85,408 | May 26, 2026 |
| May 22, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Restricted Stock Unitsderivative | -4,368 | $0.00 | $0 | 30,576 | May 26, 2026 |
| Feb 25, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +24,381 | $0.00 | $0 | 180,056 | Feb 27, 2026 |
| Feb 25, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -11,789 | $19.00 | $224k | 168,267 | Feb 27, 2026 |
| Feb 25, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Performance Restricted Stock Unitsderivative | -24,381 | $0.00 | $0 | 73,147 | Feb 27, 2026 |
| Feb 26, 2026 | TENB Tenable Holdings, Inc. | AGrant or award Restricted Stock Unitsderivative | +341,847 | $0.00 | $0 | 341,847 | Feb 27, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +1,365 | $0.00 | $0 | 115,004 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -401 | $17.55 | $7,038 | 114,603 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +1,162 | $0.00 | $0 | 115,765 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -342 | $17.55 | $6,002 | 115,423 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +2,267 | $0.00 | $0 | 117,690 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -666 | $17.55 | $12k | 117,024 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +3,857 | $0.00 | $0 | 120,881 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -1,865 | $17.55 | $33k | 119,016 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +3,713 | $0.00 | $0 | 122,729 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -1,090 | $17.55 | $19k | 121,639 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +46,586 | $0.00 | $0 | 168,225 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -15,635 | $17.55 | $274k | 152,590 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +4,368 | $0.00 | $0 | 156,958 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -1,283 | $17.55 | $23k | 155,675 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Performance Restricted Stock Unitsderivative | -1,365 | $0.00 | $0 | 0 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Performance Restricted Stock Unitsderivative | -1,162 | $0.00 | $0 | 4,654 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Performance Restricted Stock Unitsderivative | -2,267 | $0.00 | $0 | 18,140 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Restricted Stock Unitsderivative | -3,857 | $0.00 | $0 | 0 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Restricted Stock Unitsderivative | -3,713 | $0.00 | $0 | 14,852 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Restricted Stock Unitsderivative | -46,586 | $0.00 | $0 | 93,172 | Feb 25, 2026 |
| Feb 23, 2026 | TENB Tenable Holdings, Inc. | MOption exercise Restricted Stock Unitsderivative | -4,368 | $0.00 | $0 | 34,944 | Feb 25, 2026 |
| Nov 24, 2025 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +1,363 | $0.00 | $0 | 106,364 | Nov 25, 2025 |
| Nov 24, 2025 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -660 | $25.68 | $17k | 105,704 | Nov 25, 2025 |
| Nov 24, 2025 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +1,162 | $0.00 | $0 | 106,866 | Nov 25, 2025 |
| Nov 24, 2025 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -562 | $25.68 | $14k | 106,304 | Nov 25, 2025 |
| Nov 24, 2025 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +2,267 | $0.00 | $0 | 108,571 | Nov 25, 2025 |
| Nov 24, 2025 | TENB Tenable Holdings, Inc. | FTax withholding Common Stock | -1,097 | $25.68 | $28k | 107,474 | Nov 25, 2025 |
| Nov 24, 2025 | TENB Tenable Holdings, Inc. | MOption exercise Common Stock | +3,857 | $0.00 | $0 | 111,331 | Nov 25, 2025 |
50 of 107 rows shown.
Questions about Mark C. Thurmond
Answered from the filings on this page, as of the latest one.
Is Mark C. Thurmond buying or selling?
Not in the last 12 months. Mark C. Thurmond's latest open-market trade on SEC Form 4 was sold $76k of TENB on Aug 26, 2025.
How did Mark C. Thurmond's past buys perform?
Not measured yet. InsiderTell needs three past buys with six months of prices to publish a track record, and Mark C. Thurmond has 0.
Where does Mark C. Thurmond file Form 4?
Mark C. Thurmond has filed Form 4 at TENB (Tenable Holdings, Inc.) as Co-Chief Executive Officer. A Form 4 is required of officers, directors and holders of more than 10% of a share class within two business days of a trade.
Not investment advice. Scores and forward returns are decision support built from public SEC filings and past prices; they describe what happened after comparable filings, not what will happen after this one. Do your own research and size your risk.