Zanganeh Mahkam purchased ~$12M in Summit Therapeutics Inc. stock
Summit Therapeutics Inc. (SMMT) · Co-Chief Executive Officer · Data via SEC EDGAR Form 4
Price Performance · 10 days before → 90 days after trade
▲ = insider buy date
90-day return
-3.4%vs SPY +5.0%
Trade Details · Public SEC Filing
Insider
Zanganeh Mahkam
Role
Co-Chief Executive Officer
Transaction
Open-Market Purchase
Approx. Value
~$12M
Trade Date
Sep 10, 2025
Company
Summit Therapeutics Inc.
Ticker
SMMTSource
SEC EDGAR Form 4
Why This Trade Stands Out
Very Strong conviction signal
Scored in the top tier across multiple factors. Fewer than 5% of insider trades receive this rating.
~$12M purchase
Trades over $1M are rare. When insiders put this much of their own money on the line, they tend to have high conviction in their company's direction.
Co-Chief Executive Officer
CEOs have the deepest knowledge of company operations. Academic research shows CEO purchases outperform other insider trades by a wide margin.
2 insiders traded in the same window
When multiple insiders independently buy within 30 days, it's called a cluster. Studies show clustered insider purchases outperform solo trades significantly, because several people with inside knowledge are reaching the same conclusion.
-3.4% in 90 days (S&P 500: +5.0%)
This trade underperformed the S&P 500 by 8.4 percentage points. Not every insider trade wins. We track all of them so you can focus on the insiders with the best records.
How good is Zanganeh Mahkam at picking stocks?
Full track record: win rate, average return, and performance vs S&P 500
Zanganeh Mahkam wasn't the only one buying.
2 insiders at Summit Therapeutics Inc. traded within the same 30-day window.
See who else bought · FreeOn September 10, 2025, Zanganeh Mahkam — Co-Chief Executive Officer of Summit Therapeutics Inc. — filed a Form 4 with the SEC disclosing an open-market purchase of approximately ~$12M in Summit Therapeutics Inc. (SMMT) stock.
This transaction was part of a cluster — 2 insiders at Summit Therapeutics Inc. made open-market purchases within the same 30-day window. Cluster activity from multiple independent insiders is one of the most studied patterns in insider trading research.
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.
In the 90 days following this trade, SMMT returned -3.4% versus +5.0% for the S&P 500 over the same period.
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 SMMT Insider Activity
Zanganeh Mahkam
Jun 12, 2026
~$50M
VS
DUGGAN ROBERT W
Jun 12, 2026
~$350M
STRONG
DUGGAN ROBERT W
Jun 12, 2026
~$50M
VS
Soni Manmeet Singh
Jun 4, 2026
~$361K
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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