HolderBook

SIONNA THERAPEUTICS INC (SION)

Institutional ownership reported to the SEC as of Q3 2026, across 7 quarters.

2
Reporting holders
$8.6K
Reported value
0.0%
Calls
0.0%
Puts
-150
Holder change

Calls and puts are the parts of reported value carried in derivative lines rather than shares, and they point in opposite directions: a manager holding calls is positioned for the security, one holding puts against it - or hedging shares they already own, which is why index funds carry so many. Most sites add the two together and report one figure, which averages away the only interesting part.

Holders

Download these holders as CSV

FilerValueShares Their book Held Change
GAMMA Investing LLC$4.9K9250.00%5q+279.1%+$3.6K
Farther Finance Advisors, LLC$3.8K7160.00%4q+265.3%+$2.7K

Five percent filings

Anyone crossing 5% of a company must say so within days - far sooner than the next quarterly holdings report. A 13D declares an intent to influence the company; a 13G is the passive version. See all activist filings →

FiledFormFiler % of class
2026-09-2113D/ARA Capital Management, L.P.with 4 co-filers14.3%

What the company announced

Form 8-K filings from the last 120 days, showing only the items worth a reader's attention. Earnings releases, exhibit attachments and general disclosures are filed constantly and are left out. Filed is when the SEC received it; event is the date the company says the thing happened.

FiledEvent dateWhatSource
2026-09-142026-09-09Directors or officers departed or appointed Exit or disposal costsfiling

What the insiders did

Open market purchases and sales reported on Form 4 in the last 180 days. Grants, option exercises and shares surrendered to cover tax are left out: they are compensation rather than a decision to buy or sell. Where a broker filled one order in tranches the lines are summed, because it was one decision.

Officers and directors

DateInsiderRoleSideSharesValue
2026-04-15Thompson Peter A.DirectorSold235,863$10.5M
2026-04-16Thompson Peter A.DirectorSold226,906$10.3M
2026-05-11Thompson Peter A.DirectorSold184,639$8.5M
2026-06-30Thompson Peter A.DirectorSold115,844$5.3M
2026-07-07Thompson Peter A.DirectorSold85,918$3.9M
2026-05-08Thompson Peter A.DirectorSold59,767$2.7M
2026-04-17Thompson Peter A.DirectorSold52,397$2.3M
2026-05-07Thompson Peter A.DirectorSold48,546$2.2M
2026-07-06Fitzpatrick JenniferChief Legal OfficerSold10,250$446.9K
2026-04-18Thompson Peter A.DirectorSold2,948$131.2K

Ten percent owners and entities

Usually an institution that crossed a reporting threshold, or a company taking a strategic stake, rather than an individual with a view.

DateInsiderRoleSideSharesValue
2026-09-17RA CAPITAL MANAGEMENT, L.P.Director, 10% ownerSold3,448,811$21.8M ×2
2026-04-15ORBIMED ADVISORS LLCDirectorSold235,863$10.5M
2026-04-16ORBIMED ADVISORS LLCDirectorSold226,906$10.3M
2026-05-11ORBIMED ADVISORS LLCDirectorSold184,639$8.5M
2026-06-30ORBIMED ADVISORS LLCDirectorSold115,844$5.3M
2026-07-07ORBIMED ADVISORS LLCDirectorSold85,918$3.9M

Quarter by quarter

Coverage begins with the quarter ending 2018-12-31. Earlier filings exist only as occasional late amendments, too sparse to describe a market, so they are not shown.

QuarterHoldersValue SharesNewAdded TrimmedOptions
Q3 20262$8.6K1,6410200.0%
Q2 2026152$2.2B50,601,1594056400.5%
Q1 2026121$1.8B45,986,7532741280.0%
Q4 2025101$1.8B44,030,7572839200.0%
Q3 202578$1.3B44,819,1901920180.0%
Q2 202565$753.8M43,448,4512618100.0%
Q1 202547$434.1M41,491,94747000.0%