SION insider buying and SEC filings, explained
Sionna Therapeutics, Inc. · CIK 2036042
Tracked: Forms 3/4/5, 8-K, NT · All filings on sec.gov
Insider activity in the last 12 months
Bought
$0
Insiders who bought
0
Sold (not marked 10b5-1)
$38.5M
Planned sales (10b5-1)
$112.6M
Insider purchases and sales, last 12 months
| Traded | Type | What was filed | Source |
|---|---|---|---|
| Sep 17, 2026 | Sale | Peter Kolchinsky (Director and 10% owner) sold 3,448,811 shares indirectly at about $6.33 ($21.8M). Indirect holdings down 50% to 3,448,812 shares. Not marked as a 10b5-1 plan trade. Filed jointly with 5 other reporting owners. | SEC filing Filed Sep 21, 2026 |
| Jul 7, 2026 | Planned (10b5-1) | Peter A. Thompson (Director) sold 85,918 shares indirectly at $44.86 ($3.9M), marked as a 10b5-1 plan trade. Indirect holdings down 3% to 2,469,959 shares. | SEC filing Filed Jul 9, 2026 |
| Jul 7, 2026 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 85,918 shares indirectly at $44.86 ($3.9M), marked as a 10b5-1 plan trade. Indirect holdings down 3% to 2,469,959 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed Jul 9, 2026 |
| Jul 6, 2026 | Planned (10b5-1) | Jennifer Fitzpatrick (Chief Legal Officer) sold 10,250 shares at about $43.60 ($447K), marked as a 10b5-1 plan trade. Holdings down 100% to 0 shares. | SEC filing Filed Jul 7, 2026 |
| Jun 30, 2026 | Planned (10b5-1) | Peter A. Thompson (Director) sold 115,844 shares indirectly at $45.50 ($5.3M), marked as a 10b5-1 plan trade. Indirect holdings down 4% to 2,555,877 shares. | SEC filing Filed Jul 2, 2026 |
| Jun 30, 2026 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 115,844 shares indirectly at $45.50 ($5.3M), marked as a 10b5-1 plan trade. Indirect holdings down 4% to 2,555,877 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed Jul 2, 2026 |
| May 27, 2026 | Planned (10b5-1) | Peter A. Thompson (Director) sold 101 shares indirectly at $44.49 ($4K), marked as a 10b5-1 plan trade. Indirect holdings down <1% to 2,671,721 shares. | SEC filing Filed May 29, 2026 |
| May 27, 2026 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 101 shares indirectly at $44.49 ($4K), marked as a 10b5-1 plan trade. Indirect holdings down <1% to 2,671,721 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed May 29, 2026 |
| May 7–11, 2026 | Planned (10b5-1) | Peter A. Thompson (Director) sold 292,952 shares indirectly between May 7 and May 11 at about $45.62 ($13.4M), marked as a 10b5-1 plan trade. Indirect holdings down 10% to 2,671,822 shares. | SEC filing Filed May 11, 2026 |
| May 7–11, 2026 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 292,952 shares indirectly between May 7 and May 11 at about $45.62 ($13.4M), marked as a 10b5-1 plan trade. Indirect holdings down 10% to 2,671,822 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed May 11, 2026 |
| Apr 17–18, 2026 | Planned (10b5-1) | Peter A. Thompson (Director) sold 55,345 shares indirectly between Apr 17 and Apr 18 at about $44.67 ($2.5M), marked as a 10b5-1 plan trade. Indirect holdings down 2% to 2,964,774 shares. | SEC filing Filed Apr 21, 2026 |
| Apr 17–18, 2026 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 55,345 shares indirectly between Apr 17 and Apr 18 at about $44.67 ($2.5M), marked as a 10b5-1 plan trade. Indirect holdings down 2% to 2,964,774 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed Apr 21, 2026 |
| Apr 14–16, 2026 | Planned (10b5-1) | Peter A. Thompson (Director) sold 510,583 shares indirectly between Apr 14 and Apr 16 at about $44.94 ($22.9M), marked as a 10b5-1 plan trade. Indirect holdings down 14% to 3,020,119 shares. | SEC filing Filed Apr 16, 2026 |
| Apr 14–16, 2026 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 510,583 shares indirectly between Apr 14 and Apr 16 at about $44.94 ($22.9M), marked as a 10b5-1 plan trade. Indirect holdings down 14% to 3,020,119 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed Apr 16, 2026 |
| Mar 5, 2026 | Planned (10b5-1) | Jennifer Fitzpatrick (Chief Legal Officer) sold 10,250 shares at about $33.86 ($347K), marked as a 10b5-1 plan trade. Holdings down 100% to 0 shares. | SEC filing Filed Mar 6, 2026 |
| Feb 2–3, 2026 | Planned (10b5-1) | Peter A. Thompson (Director) sold 30,953 shares indirectly between Feb 2 and Feb 3 at about $44.58 ($1.4M), marked as a 10b5-1 plan trade. Indirect holdings down 1% to 3,530,702 shares. | SEC filing Filed Feb 4, 2026 |
| Feb 2–3, 2026 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 30,953 shares indirectly between Feb 2 and Feb 3 at about $44.58 ($1.4M), marked as a 10b5-1 plan trade. Indirect holdings down 1% to 3,530,702 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed Feb 4, 2026 |
| Jan 22, 2026 | Sale | James G. Coulter (10% owner) sold 250,000 shares indirectly at $40.00 ($10.0M). Indirect holdings down 4% to 6,494,962 shares. Not marked as a 10b5-1 plan trade. Filed jointly with 2 other reporting owners. | SEC filing Filed Jan 26, 2026 |
| Dec 24, 2025 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 33,356 shares indirectly at $44.55 ($1.5M), marked as a 10b5-1 plan trade. Indirect holdings down 1% to 3,561,655 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed Dec 29, 2025 |
| Dec 24, 2025 | Planned (10b5-1) | Peter A. Thompson (Director) sold 33,356 shares indirectly at $44.55 ($1.5M), marked as a 10b5-1 plan trade. Indirect holdings down 1% to 3,561,655 shares. | SEC filing Filed Dec 29, 2025 |
| Dec 17–19, 2025 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 1,875 shares indirectly between Dec 17, 2025 and Dec 19, 2025 at about $44.49 ($83K), marked as a 10b5-1 plan trade. Indirect holdings down <1% to 3,595,011 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed Dec 19, 2025 |
| Dec 17–19, 2025 | Planned (10b5-1) | Peter A. Thompson (Director) sold 1,875 shares indirectly between Dec 17, 2025 and Dec 19, 2025 at about $44.49 ($83K), marked as a 10b5-1 plan trade. Indirect holdings down <1% to 3,595,011 shares. | SEC filing Filed Dec 19, 2025 |
| Dec 5, 2025 | Planned (10b5-1) | Jennifer Fitzpatrick (Chief Legal Officer) sold 10,250 shares at about $40.52 ($415K), marked as a 10b5-1 plan trade. Holdings down 100% to 0 shares. | SEC filing Filed Dec 9, 2025 |
| Nov 24–26, 2025 | Planned (10b5-1) | ORBIMED ADVISORS LLC (Director) sold 108,073 shares indirectly between Nov 24, 2025 and Nov 26, 2025 at about $44.55 ($4.8M), marked as a 10b5-1 plan trade. Indirect holdings down 3% to 3,596,886 shares. Filed jointly with 1 other reporting owner. | SEC filing Filed Nov 26, 2025 |
| Nov 24–26, 2025 | Planned (10b5-1) | Peter A. Thompson (Director) sold 108,073 shares indirectly between Nov 24, 2025 and Nov 26, 2025 at about $44.55 ($4.8M), marked as a 10b5-1 plan trade. Indirect holdings down 3% to 3,596,886 shares. | SEC filing Filed Nov 26, 2025 |
| Nov 20–21, 2025 | Sale | Peter Kolchinsky (Director and 10% owner) sold 30,316 shares indirectly between Nov 20, 2025 and Nov 21, 2025 at about $39.61 ($1.2M). Indirect holdings down 16% to 159,033 shares. Not marked as a 10b5-1 plan trade. Filed jointly with 5 other reporting owners. | SEC filing Filed Nov 24, 2025 |
| Nov 17–19, 2025 | Sale | Peter Kolchinsky (Director and 10% owner) sold 136,351 shares indirectly between Nov 17, 2025 and Nov 19, 2025 at about $40.34 ($5.5M). Indirect holdings down 45% to 168,193 shares. Not marked as a 10b5-1 plan trade. Filed jointly with 5 other reporting owners. | SEC filing Filed Nov 19, 2025 |
21 routine transactions (such as grants, option exercises or tax withholding) are not listed.
Cluster buys
No cluster buys in the last 12 months.
Red flags
No red flags in the last 12 months.
Key events
No key events in the last 12 months.
8-K filings, last 12 months
No 8-K filings in the last 12 months.
Red flags are objective triggers only: the item or form filed, never an opinion.
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