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sellWeak cluster of 210b5-1 plan

Bruce Booth sold $1.5M of SION

director at Sionna Therapeutics, Inc.. 49,546 shares at an average of $29.99, traded Oct 3, 2025, filed Oct 7, 2025.

Warning score
28
Value
$1.5M
49,546 shares
Holdings after
785,480
-2% from before
From 52-week low
+292%
low $7.66, close $30.01
From 52-week high
0%
high $30.01, as of Oct 3, 2025

Score components

  • Role
    Director
    +15
  • Trade size
    $1.5M at market
    +25
  • Share of holdings sold
    Sold 1.8% of holdings
    0
  • Cluster
    2 insiders selling within 14 days
    +8
  • 10b5-1 plan
    Pre-scheduled under a 10b5-1 plan
    -20

What happened after comparable sells

Same side and tier, against the S&P 500, at 1, 3 and 6 months. Shown to Pro users; the whole table is on the backtest page.

This signal so far: 1m +20.2%, 3m +30.1%, 6m +28.5%.

Price around the trade, and since

From a quarter before the trade to today. The arrow is the trade, the circle the day the filing reached EDGAR, which is the first day anyone outside could act; the dotted line is the S&P 500 rebased to that day's close.

SIONOct 12, 2026 · close 4.69
Since filing Oct 7, 2025: -83.6%SPY +17.5% · excess -101.1%

Daily candles, adjusted for splits and dividends. Green arrows are insider buys, red are sells, sized by value; the dashed line is the close on the filing day, the dotted line SPY rebased to it.Charts by TradingView Lightweight Charts™

Rows in this filing

Every transaction in Form 4 0001451612-25-000006, as filed. Open on EDGAR

DateTransactionSharesPriceValueHoldings afterFiled
Oct 3, 2025SOpen-market sale
Common Stockindirect: By Atlas Venture Fund XI, L.P.10b5-1
-31,198$30.00$936k2,790,054Oct 7, 2025
Oct 3, 2025SOpen-market sale
Common Stockindirect: By Atlas Venture Opportunity Fund II, L.P.10b5-1
-6,548$30.00$196k787,527Oct 7, 2025
Oct 6, 2025SOpen-market sale
Common Stockindirect: By Atlas Venture Fund XI, L.P.10b5-1
-9,753$29.95$292k2,780,301Oct 7, 2025
Oct 6, 2025SOpen-market sale
Common Stockindirect: By Atlas Venture Opportunity Fund II, L.P.10b5-1
-2,047$29.95$61k785,480Oct 7, 2025

Related signals

Other insiders at Sionna Therapeutics, Inc. and this insider’s other filings.

ScoreCompanyInsiderValueHoldingsFiled
50Moderate
SIONsell
Sionna Therapeutics, Inc.
Ra Capital Management, L.p.
director, owner
$22M
3,448,811 shares
-50%
35Weak
SIONsell 310b5-1
Sionna Therapeutics, Inc.
Orbimed Advisors LLC
director
$3.9M
85,918 shares
-3%
35Weak
SIONsell 310b5-1
Sionna Therapeutics, Inc.
Peter A. Thompson
director
$3.9M
85,918 shares
-3%
32Weak
SIONsell 310b5-1
Sionna Therapeutics, Inc.
Jennifer Fitzpatrick
Chief Legal Officer
$447k
10,250 shares
-100%
35Weak
SIONsell 310b5-1
Sionna Therapeutics, Inc.
Orbimed Advisors LLC
director
$5.3M
115,844 shares
-4%
35Weak
SIONsell 310b5-1
Sionna Therapeutics, Inc.
Peter A. Thompson
director
$5.3M
115,844 shares
-4%
3Weak
SIONsell 210b5-1
Sionna Therapeutics, Inc.
Orbimed Advisors LLC
director
$4,493
101 shares
-0%
3Weak
SIONsell 210b5-1
Sionna Therapeutics, Inc.
Peter A. Thompson
director
$4,493
101 shares
-0%
28Weak
SIONsell 210b5-1
Sionna Therapeutics, Inc.
Orbimed Advisors LLC
director
$13M
292,952 shares
-10%
28Weak
SIONsell 210b5-1
Sionna Therapeutics, Inc.
Peter A. Thompson
director
$13M
292,952 shares
-10%

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.

Bruce Booth sold $1.5M of SION | InsiderTell