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sellWeak cluster of 310b5-1 plan

William Lewis sold $1.5M of INSM

Chair and CEO at INSMED Inc. 10,699 shares at an average of $143.52, traded Mar 19, 2026, filed Mar 20, 2026.

Warning score
30
Value
$1.5M
10,699 shares
Holdings after
301,185
-3% from before
From 52-week low
+122%
low $64.81, close $144.00
From 52-week high
-32%
high $211.41, as of Mar 19, 2026

Score components

  • Role
    CEO
    +25
  • Trade size
    $1.5M at market
    +25
  • Share of holdings sold
    Sold 3.4% of holdings
    0
  • Cluster
    3 insiders selling within 14 days
    +15
  • Exercise and sell
    Shares came from an option exercise in the same filing
    -15
  • 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 +6.2%, 3m -29.6%, 6m -11.8%.

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.

INSMOct 13, 2026 · close 96.79
Since filing Mar 20, 2026: -28.8%SPY +20.6% · excess -49.4%

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 0001402051-26-000020, as filed. Open on EDGAR

DateTransactionSharesPriceValueHoldings afterFiled
Mar 19, 2026MOption exercise
Common Stock10b5-1
+6,259$30.46$191k307,444Mar 20, 2026
Mar 19, 2026MOption exercise
Common Stock10b5-1
+4,440$17.16$76k311,884Mar 20, 2026
Mar 19, 2026SOpen-market sale
Common Stock10b5-1
-1,629$142.17$232k310,255Mar 20, 2026
Mar 19, 2026SOpen-market sale
Common Stock10b5-1
-4,537$143.42$651k305,718Mar 20, 2026
Mar 19, 2026SOpen-market sale
Common Stock10b5-1
-4,533$144.11$653k301,185Mar 20, 2026
Mar 19, 2026MOption exercise
Stock Option (right to buy)derivative10b5-1
-6,259$0.00$050,073Mar 20, 2026
Mar 19, 2026MOption exercise
Stock Option (right to buy)derivative10b5-1
-4,440$0.00$035,520Mar 20, 2026

Related signals

Other insiders at INSMED Inc and this insider’s other filings.

ScoreCompanyInsiderValueHoldingsFiled
50Moderate
INSMsell
INSMED Inc
David R Brennan
director
$3.1M
25,000 shares
-39%
70Notable
INSMsell 3
INSMED Inc
Melvin Sharoky Md
director
$638k
5,000 shares
-100%
65Notable
INSMsell 3
INSMED Inc
Roger Adsett
Chief Operating Officer
$32M
239,850 shares
-71%
30Weak
INSMsell 410b5-1
INSMED Inc
Martina Flammer M.D.
Chief Medical Officer
$3.5M
27,173 shares
-31%
23Weak
INSMsell 210b5-1
INSMED Inc
William Lewis
Chair and CEO
$1.1M
10,700 shares
-4%
23Weak
INSMsell 210b5-1
INSMED Inc
William Lewis
Chair and CEO
$1.3M
10,699 shares
-4%
25Weak
INSMsell 310b5-1
INSMED Inc
Martina Flammer M.D.
Chief Medical Officer
$1.4M
12,302 shares
-17%
30Weak
INSMsell 310b5-1
INSMED Inc
William Lewis
Chair and CEO
$2.2M
21,398 shares
-8%
21Weak
INSMsell 310b5-1
INSMED Inc
Michael Alexander Smith
Chief Legal Officer
$173k
1,806 shares
-5%
40Moderate
INSMsell 510b5-1
INSMED Inc
William Lewis
Chair and CEO
$613k
6,515 shares
-2%

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.

William Lewis sold $1.5M of INSM | InsiderTell