Form 4 for SION Sionna Therapeutics, Inc.
Accepted 2025-10-15 00:00:00 ET · period of report 2025-10-10 · accession 0001451612-25-000008 · SEC index · Original document
Summary rows
Aggregated the way they appear in lists: one row per insider, transaction code and security table.
| X | Filed | Traded | Ticker | Insider | Title | Type | Price | Qty | Owned | ΔOwn | Value |
|---|---|---|---|---|---|---|---|---|---|---|---|
| MI | 2025-10-15 | 2025-10-10+ | SION | Booth Bruce | Dir | S - Sale | $30.47 | -194.9K | 771.8K | -20% | -$5.94M |
Purchase Sale Sale after option exercise All abbreviations
Every reported transaction
| # | Table | Security | Date | Code | A/D | Shares | Price | Owned after | Own | Exercise / expiry | Underlying | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Common | Common Stock | 2025-10-15 | S | D | 6,303 | $31.12 | 751,664 | I By Atlas Venture Opportunity Fund II, L.P. | — | — | (F8) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.95 to $31.30 inclusive. (F5) These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any. |
| 2 | Common | Common Stock | 2025-10-10 | S | D | 16,727 | $29.98 | 2,763,574 | I By Atlas Venture Fund XI, L.P. | — | — | (F2) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.11 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2), (6), (7) and (8). (F3) These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any. |
| 3 | Common | Common Stock | 2025-10-10 | S | D | 3,511 | $29.98 | 781,969 | I By Atlas Venture Opportunity Fund II, L.P. | — | — | (F2) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.11 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2), (6), (7) and (8). (F5) These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any. |
| 4 | Common | Common Stock | 2025-10-13 | S | D | 44,048 | $30.32 | 2,719,526 | I By Atlas Venture Fund XI, L.P. | — | — | (F6) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.93 inclusive. (F3) These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any. |
| 5 | Common | Common Stock | 2025-10-13 | S | D | 9,245 | $30.32 | 772,724 | I By Atlas Venture Opportunity Fund II, L.P. | — | — | (F6) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.93 inclusive. (F5) These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any. |
| 6 | Common | Common Stock | 2025-10-13 | S | D | 4,082 | $31.03 | 2,715,444 | I By Atlas Venture Fund XI, L.P. | — | — | (F3) These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any. |
| 7 | Common | Common Stock | 2025-10-13 | S | D | 857 | $31.03 | 771,867 | I By Atlas Venture Opportunity Fund II, L.P. | — | — | (F5) These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any. |
| 8 | Common | Common Stock | 2025-10-14 | S | D | 501 | $29.95 | 2,714,943 | I By Atlas Venture Fund XI, L.P. | — | — | (F3) These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any. |
| 9 | Common | Common Stock | 2025-10-15 | S | D | 30,032 | $31.12 | 2,619,185 | I By Atlas Venture Fund XI, L.P. | — | — | (F8) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $30.95 to $31.30 inclusive. (F3) These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any. |
| 10 | Common | Common Stock | 2025-10-15 | S | D | 13,795 | $30.37 | 757,967 | I By Atlas Venture Opportunity Fund II, L.P. | — | — | (F7) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.94 inclusive. (F5) These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any. |
| 11 | Common | Common Stock | 2025-10-15 | S | D | 65,726 | $30.37 | 2,649,217 | I By Atlas Venture Fund XI, L.P. | — | — | (F7) The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $29.95 to $30.94 inclusive. (F3) These shares are held directly by Atlas Venture Fund XI, L.P. ("AVF XI "). The general partner of AVF XI is Atlas Venture Associates XI, L.P. ("AVA XI LP"). Atlas Venture Associates XI, LLC ("AVA XI LLC") is the general partner of AVA XI LP. The Reporting Person is a member of AVA XI LLC and disclaims beneficial ownership of such securities held by AVF XI, except to the extent of his pecuniary interest therein, if any. |
| 12 | Common | Common Stock | 2025-10-14 | S | D | 105 | $29.95 | 771,762 | I By Atlas Venture Opportunity Fund II, L.P. | — | — | (F5) These shares are held directly by Atlas Venture Opportunity Fund II, L.P. ("AVOF II"). The general partner of AVOF II is Atlas Venture Associates Opportunity II, L.P. ("AVAO II LP"). Atlas Venture Associates Opportunity II, LLC ("AVAO II LLC") is the general partner of AVAO II LP. The Reporting Person is a member of AVAO II LLC and disclaims beneficial ownership of such securities held by AVOF II, except to the extent of his pecuniary interest therein, if any. |