Sionna Therapeutics Inc. Insider Trading

SION

Last 12 months

Insiders sold $58.1M and bought nothing on the open market.

98% of the selling was scheduled in advance under 10b5-1 plans. Director Peter Kolchinsky sold $1.2M on Nov 21, 2025, 16% of their stake, outside a plan. The last open-market buy by an executive or director was in Feb 2025.

Net open-market

−$58.1M

0 buys · 14 sales

Under a 10b5-1 plan

98%

of the value sold

Insiders who bought / sold

0 / 3

executives and directors

Last open-market buy

Feb 2025

Feb 10, 2025

Get an email when SION's executives or directors buy, or make a large sale outside a plan.

Trades · last 2 years

Date	Insider	Trade	Shares	Price	Value	Of their stake	Filing
Sep 17	RA Capital Management, L.p. Large holder	SoldNo plan 2 parts	3,448,811	$6.33 average	$21.8M	50%	Form 4
Jul 7	Peter A. Thompson Director	Sold10b5-1 plan	85,918	$44.86	$3.85M	3.4%	Form 4
Jul 7	Orbimed Capital GP Viii LLC Large holder	Sold10b5-1 plan	85,918	$44.86	$3.85M	3.4%	Form 4
Jul 6	Jennifer Fitzpatrick Chief Legal Officer	Sold10b5-1 plan	10,250	$43.60	447K	100%	Form 4
Jun 30	Peter A. Thompson Director	Sold10b5-1 plan	115,844	$45.50	$5.27M	4.3%	Form 4
Jun 30	Orbimed Advisors LLC Large holder	Sold10b5-1 plan	115,844	$45.50	$5.27M	4.3%	Form 4
May 27	Peter A. Thompson Director	Sold10b5-1 plan	101	$44.49	4K	<0.1%	Form 4
May 27	Orbimed Advisors LLC Large holder	Sold10b5-1 plan	101	$44.49	4K	<0.1%	Form 4
May 7 – 11	Peter A. Thompson Director	Sold10b5-1 plan 3 parts	292,952	$45.62 average	$13.4M	9.9%	Form 4
May 7 – 11	Orbimed Advisors LLC Large holder	Sold10b5-1 plan 3 parts	292,952	$45.62 average	$13.4M	9.9%	Form 4
Apr 17 – 18	Peter A. Thompson Director	Sold10b5-1 plan 2 parts	55,345	$44.67 average	$2.47M	1.8%	Form 4
Apr 17 – 18	Orbimed Advisors LLC Large holder	Sold10b5-1 plan 2 parts	55,345	$44.67 average	$2.47M	1.8%	Form 4
Apr 14 – 16	Peter A. Thompson Director	Sold10b5-1 plan 3 parts	510,583	$44.94 average	$22.9M	14%	Form 4
Apr 14 – 16	Orbimed Advisors LLC Large holder	Sold10b5-1 plan 3 parts	510,583	$44.94 average	$22.9M	14%	Form 4
Mar 5	Jennifer Fitzpatrick Chief Legal Officer	Sold10b5-1 plan	10,250	$33.86	347K	100%	Form 4
Feb 2 – 3	Peter A. Thompson Director	Sold10b5-1 plan 2 parts	30,953	$44.58 average	$1.38M	0.9%	Form 4
Feb 2 – 3	Orbimed Capital GP Viii LLC Large holder	Sold10b5-1 plan 2 parts	30,953	$44.58 average	$1.38M	0.9%	Form 4
Jan 22	Jon Winkelried Large holder	SoldNo plan	250,000	$40.00	$10M	3.7%	Form 4
Dec 24, 2025	Orbimed Capital GP Viii LLC Large holder	Sold10b5-1 plan	33,356	$44.55	$1.49M	0.9%	Form 4
Dec 24, 2025	Peter A. Thompson Director	Sold10b5-1 plan	33,356	$44.55	$1.49M	0.9%	Form 4
Dec 17, 2025 – Dec 19, 2025	Orbimed Capital GP Viii LLC Large holder	Sold10b5-1 plan 3 parts	1,875	$44.49 average	83K	<0.1%	Form 4
Dec 17, 2025 – Dec 19, 2025	Peter A. Thompson Director	Sold10b5-1 plan 3 parts	1,875	$44.49 average	83K	<0.1%	Form 4
Dec 5, 2025	Jennifer Fitzpatrick Chief Legal Officer	Sold10b5-1 plan	10,250	$40.52	415K	100%	Form 4
Nov 24, 2025 – Nov 26, 2025	Orbimed Advisors LLC Large holder	Sold10b5-1 plan 3 parts	108,073	$44.55 average	$4.81M	2.9%	Form 4
Nov 24, 2025 – Nov 26, 2025	Peter A. Thompson Director	Sold10b5-1 plan 3 parts	108,073	$44.55 average	$4.81M	2.9%	Form 4
Nov 20, 2025 – Nov 21, 2025	Peter Kolchinsky Director	SoldNo plan 12 parts	30,316	$39.61 average	$1.2M	16%	Form 4
Nov 17, 2025 – Nov 19, 2025	RA Capital Management, L.p. Large holder	SoldNo plan 24 parts	136,351	$40.34 average	$5.5M	45%	Form 4
Oct 24, 2025 – Oct 28, 2025	RA Capital Nexus Fund Iii, L.p. Large holder	SoldNo plan 8 parts	373,610	$39.51 average	$14.8M	64%	Form 4
Oct 21, 2025	Michael Cloonan President & CEO	Sold10b5-1 plan 4 parts	99,800	$36.26 average	$3.62M	15%	Form 4
Oct 21, 2025	Bruce Booth Director	Sold10b5-1 plan 10 parts	88,878	$34.22 average	$3.04M	2.9%	Form 4
Oct 16, 2025 – Oct 20, 2025	Bruce Booth Director	Sold10b5-1 plan 18 parts	286,369	$32.30 average	$9.25M	8.5%	Form 4
Oct 15, 2025 – Oct 16, 2025	Michael Cloonan President & CEO	Sold10b5-1 plan 3 parts	25,200	$31.27 average	788K	4.4%	Form 4
Oct 10, 2025 – Oct 15, 2025	Bruce Booth Director	Sold10b5-1 plan 12 parts	194,932	$30.47 average	$5.94M	5.5%	Form 4
Oct 3, 2025 – Oct 6, 2025	Bruce Booth Director	Sold10b5-1 plan 4 parts	49,546	$29.99 average	$1.49M	1.4%	Form 4
Sep 29, 2025 – Oct 1, 2025	Bruce Booth Director	Sold10b5-1 plan 6 parts	78,693	$30.08 average	$2.37M	2.1%	Form 4
Sep 26, 2025 – Sep 29, 2025	Michael Cloonan President & CEO	Sold10b5-1 plan 2 parts	25,000	$29.11 average	728K	4.4%	Form 4
Sep 4, 2025	Jennifer Fitzpatrick Chief Legal Officer	Sold10b5-1 plan	10,250	$23.12	237K	100%	Form 4
Aug 29, 2025 – Sep 2, 2025	Elena Ridloff CFO & Head of Corp. Dev.	Sold10b5-1 plan 2 parts	9,584	$25.09 average	240K	20%	Form 4
Aug 26, 2025 – Aug 28, 2025	Elena Ridloff CFO & Head of Corp. Dev.	Sold10b5-1 plan 3 parts	23,416	$25.70 average	602K	33%	Form 4
Aug 26, 2025 – Aug 27, 2025	Michael Cloonan President & CEO	Sold10b5-1 plan 2 parts	25,000	$24.97 average	624K	4.4%	Form 4

Sep 17No plan
RA Capital Management, L.p.
Large holder · sold 3,448,811 at avg $6.33
$21.8M
50% of stake
Jul 710b5-1 plan
Peter A. Thompson
Director · sold 85,918 at $44.86
$3.85M
3.4% of stake
Jul 710b5-1 plan
Orbimed Capital GP Viii LLC
Large holder · sold 85,918 at $44.86
$3.85M
3.4% of stake
Jul 610b5-1 plan
Jennifer Fitzpatrick
Chief Legal Officer · sold 10,250 at $43.60
447K
100% of stake
Jun 3010b5-1 plan
Peter A. Thompson
Director · sold 115,844 at $45.50
$5.27M
4.3% of stake
Jun 3010b5-1 plan
Orbimed Advisors LLC
Large holder · sold 115,844 at $45.50
$5.27M
4.3% of stake
May 2710b5-1 plan
Peter A. Thompson
Director · sold 101 at $44.49
4K
<0.1% of stake
May 2710b5-1 plan
Orbimed Advisors LLC
Large holder · sold 101 at $44.49
4K
<0.1% of stake
May 7 – 1110b5-1 plan
Peter A. Thompson
Director · sold 292,952 at avg $45.62
$13.4M
9.9% of stake
May 7 – 1110b5-1 plan
Orbimed Advisors LLC
Large holder · sold 292,952 at avg $45.62
$13.4M
9.9% of stake
Apr 17 – 1810b5-1 plan
Peter A. Thompson
Director · sold 55,345 at avg $44.67
$2.47M
1.8% of stake
Apr 17 – 1810b5-1 plan
Orbimed Advisors LLC
Large holder · sold 55,345 at avg $44.67
$2.47M
1.8% of stake
Apr 14 – 1610b5-1 plan
Peter A. Thompson
Director · sold 510,583 at avg $44.94
$22.9M
14% of stake
Apr 14 – 1610b5-1 plan
Orbimed Advisors LLC
Large holder · sold 510,583 at avg $44.94
$22.9M
14% of stake
Mar 510b5-1 plan
Jennifer Fitzpatrick
Chief Legal Officer · sold 10,250 at $33.86
347K
100% of stake
Feb 2 – 310b5-1 plan
Peter A. Thompson
Director · sold 30,953 at avg $44.58
$1.38M
0.9% of stake
Feb 2 – 310b5-1 plan
Orbimed Capital GP Viii LLC
Large holder · sold 30,953 at avg $44.58
$1.38M
0.9% of stake
Jan 22No plan
Jon Winkelried
Large holder · sold 250,000 at $40.00
$10M
3.7% of stake
Dec 24, 202510b5-1 plan
Orbimed Capital GP Viii LLC
Large holder · sold 33,356 at $44.55
$1.49M
0.9% of stake
Dec 24, 202510b5-1 plan
Peter A. Thompson
Director · sold 33,356 at $44.55
$1.49M
0.9% of stake
Dec 17, 2025 – Dec 19, 202510b5-1 plan
Orbimed Capital GP Viii LLC
Large holder · sold 1,875 at avg $44.49
83K
<0.1% of stake
Dec 17, 2025 – Dec 19, 202510b5-1 plan
Peter A. Thompson
Director · sold 1,875 at avg $44.49
83K
<0.1% of stake
Dec 5, 202510b5-1 plan
Jennifer Fitzpatrick
Chief Legal Officer · sold 10,250 at $40.52
415K
100% of stake
Nov 24, 2025 – Nov 26, 202510b5-1 plan
Orbimed Advisors LLC
Large holder · sold 108,073 at avg $44.55
$4.81M
2.9% of stake
Nov 24, 2025 – Nov 26, 202510b5-1 plan
Peter A. Thompson
Director · sold 108,073 at avg $44.55
$4.81M
2.9% of stake
Nov 20, 2025 – Nov 21, 2025No plan
Peter Kolchinsky
Director · sold 30,316 at avg $39.61
$1.2M
16% of stake
Nov 17, 2025 – Nov 19, 2025No plan
RA Capital Management, L.p.
Large holder · sold 136,351 at avg $40.34
$5.5M
45% of stake
Oct 24, 2025 – Oct 28, 2025No plan
RA Capital Nexus Fund Iii, L.p.
Large holder · sold 373,610 at avg $39.51
$14.8M
64% of stake
Oct 21, 202510b5-1 plan
Michael Cloonan
President & CEO · sold 99,800 at avg $36.26
$3.62M
15% of stake
Oct 21, 202510b5-1 plan
Bruce Booth
Director · sold 88,878 at avg $34.22
$3.04M
2.9% of stake
Oct 16, 2025 – Oct 20, 202510b5-1 plan
Bruce Booth
Director · sold 286,369 at avg $32.30
$9.25M
8.5% of stake
Oct 15, 2025 – Oct 16, 202510b5-1 plan
Michael Cloonan
President & CEO · sold 25,200 at avg $31.27
788K
4.4% of stake
Oct 10, 2025 – Oct 15, 202510b5-1 plan
Bruce Booth
Director · sold 194,932 at avg $30.47
$5.94M
5.5% of stake
Oct 3, 2025 – Oct 6, 202510b5-1 plan
Bruce Booth
Director · sold 49,546 at avg $29.99
$1.49M
1.4% of stake
Sep 29, 2025 – Oct 1, 202510b5-1 plan
Bruce Booth
Director · sold 78,693 at avg $30.08
$2.37M
2.1% of stake
Sep 26, 2025 – Sep 29, 202510b5-1 plan
Michael Cloonan
President & CEO · sold 25,000 at avg $29.11
728K
4.4% of stake
Sep 4, 202510b5-1 plan
Jennifer Fitzpatrick
Chief Legal Officer · sold 10,250 at $23.12
237K
100% of stake
Aug 29, 2025 – Sep 2, 202510b5-1 plan
Elena Ridloff
CFO & Head of Corp. Dev. · sold 9,584 at avg $25.09
240K
20% of stake
Aug 26, 2025 – Aug 28, 202510b5-1 plan
Elena Ridloff
CFO & Head of Corp. Dev. · sold 23,416 at avg $25.70
602K
33% of stake
Aug 26, 2025 – Aug 27, 202510b5-1 plan
Michael Cloonan
President & CEO · sold 25,000 at avg $24.97
624K
4.4% of stake

How to read this. Insiders sell for many reasons: taxes, diversifying, a house. Open-market buys are rarer and say more. A 10b5-1 plan is a trading schedule set up months in advance, so those sales were not timed on news. Large holders (funds and 10% owners) are listed under Everything but not counted as insiders. If you own or watch SION, we send a push when an executive buys or makes a large sale outside a plan.

Source: SEC Form 4 filings, filed within two business days of each trade and checked for new ones every hour.

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Held by ETFs

SION is in 19 US ETFs. The largest of them, with SION's weight in each:

Spot a number that looks wrong? Check it in SION's SEC filings or

Download this analysis as a PDF (Pro)

Data sourced from SEC EDGAR filings and third-party price providers. Scores, valuations, and metrics are algorithmic estimates. This is not investment advice. See our Terms and Methodology.

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