Lewis William sold ~$778K in INSM stock
INSM (INSM) · Chair and CEO · Data via SEC EDGAR Form 4
Price Performance · 10 days before → 90 days after trade
▲ = insider buy date
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Trade Details · Public SEC Filing
Insider
Lewis William
Role
Chair and CEO
Transaction
Open-Market Sale
Approx. Value
~$778K
Trade Date
Jun 3, 2026
Company
INSM
Ticker
INSMSource
SEC EDGAR Form 4
Why This Trade Stands Out
Strong conviction signal
Scored above average across multiple factors. Roughly 15% of insider trades qualify as Strong.
~$778K sale
A significant position. Insiders who invest $500K+ of their own money typically have strong views on their company's near-term outlook.
Chair and CEO
CEOs have the deepest knowledge of company operations. Academic research shows CEO purchases outperform other insider trades by a wide margin.
How good is Lewis William at picking stocks?
Full track record: win rate, average return, and performance vs S&P 500
On June 3, 2026, Lewis William — Chair and CEO of INSM — filed a Form 4 with the SEC disclosing an open-market sale of approximately ~$778K in INSM (INSM) stock.
Under Section 16(a) of the Securities Exchange Act of 1934, corporate insiders must report all open-market stock transactions to the SEC within two business days. These filings — known as Form 4s — are publicly available on the SEC's EDGAR database. VeritySignals filters and scores the full Form 4 stream to surface high-conviction signals like this one.
VeritySignals Conviction Analysis
Full Conviction Analysis
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All data sourced from publicly available SEC Form 4 filings via EDGAR · Not financial advice · Past performance does not guarantee future results.
At a Glance
More INSM Insider Activity
Adsett Roger
May 13, 2026
~$678K
STRONG
Bonstein Sara
May 13, 2026
~$961K
STRONG
Lewis William
May 13, 2026
~$1.5M
VS
Flammer Martina M.D.
May 13, 2026
~$504K
STRONG
How to Read Insider Trades
What is this?
When company executives buy or sell their own stock, they must report it to the SEC within 2 days. These public filings reveal what the people who know the company best are doing with their own money.
Why does it matter?
Insiders can sell for many reasons (taxes, diversification, expenses), but they generally only buy for one: they think the stock is going up. That's why insider purchases are more predictive than sales.
What makes a trade "strong"?
We score trades on 15+ factors: the insider's role (CEO > director), trade size relative to their salary, whether other insiders also bought (clusters), and historical accuracy of the insider.
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