Cullinan CSO sells shares, exercises options
Cullinan Therapeutics Chief Scientific Officer Jennifer Michaelson reported an exercise-and-sell transaction in company stock.
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Form Type
4
Rhea-AI Filing Summary
Cullinan Therapeutics Chief Scientific Officer Jennifer Michaelson reported an exercise-and-sell transaction in company stock. She sold a total of 8,000 shares of Common Stock in open-market transactions at weighted average prices of $14.60 and $15.58, with actual trade prices ranging from $14.24 to $15.60. These sales were executed pursuant to a pre-established Rule 10b5-1 trading plan dated August 7, 2025. On the same day, she exercised stock options for 4,000 shares of Common Stock at an exercise price of $4.30 per share, converting a derivative position into additional common shares while using part of her holdings for liquidity.
Insider Trade Summary 10b5-1
Exercise and sale activity reported; no spread calculated
Exercise and Sale
4 txns
Insider
Michaelson Jennifer
Role
Chief Scientific Officer
Sold
8,000 shs ($117K)
Approx. gross sale proceeds
$117K
Approx. exercise cost
$17K
| Type | Security | Shares | Price | Value |
|---|---|---|---|---|
| Exercise | Stock Option (Right to Buy) | 4,000 | $0.00 | $0.00 |
| Exercise | Common Stock | 4,000 | $4.30 | $17K |
| Sale | Common Stock | 7,800 | $14.60 | $114K |
| Sale | Common Stock | 200 | $15.58 | $3K |
Holdings After Transaction:
Stock Option (Right to Buy) — 116,987 contracts (Direct);
Common Stock — 166,844 shares (Direct)
Footnotes (4)
- F1. Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025.
- F2. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $14.24 to $15.12. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F3. The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $15.56 to $15.60. The Reporting Person undertakes to provide to the Issuer, any shareholder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.
- F4. 25% of the shares vested on July 4, 2020, and the remaining shares vested in 36 equal monthly installments thereafter.
Key Figures
Shares sold: 8,000 shares
Weighted average sale price block 1: $14.60 per share
Weighted average sale price block 2: $15.58 per share
+3 more
6 metrics
Shares sold
8,000 shares
Open-market sales of Common Stock on May 5, 2026
Weighted average sale price block 1
$14.60 per share
7,800-share sale block on May 5, 2026
Weighted average sale price block 2
$15.58 per share
200-share sale block on May 5, 2026
Sale price range
$14.24–$15.60
Multiple transactions across this intraday range
Options exercised
4,000 shares
Stock Option (Right to Buy) converted into Common Stock
Option exercise price
$4.30 per share
Exercise price for 4,000-share stock option
Key Terms
Rule 10b5-1, weighted average price, Stock Option (Right to Buy), derivative security, +1 more
5 terms
Rule 10b5-1 regulatory
"Transaction effected pursuant to a plan established pursuant to Rule 10b5-1 on August 7, 2025."
Rule 10b5-1 is a regulation that allows company insiders to buy or sell their shares at predetermined times, even if they have access to non-public information. It acts like setting a schedule in advance for transactions, helping prevent accusations of unfair trading. This rule provides a way for insiders to plan trades transparently, giving investors confidence that these transactions are not based on hidden information.
weighted average price financial
"The price reported in Column 4 is a weighted average price."
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
Stock Option (Right to Buy) financial
"security_title": "Stock Option (Right to Buy)""
derivative security financial
"Exercise or conversion of derivative security"
A derivative security is a financial contract whose value comes from the price or performance of something else, such as a stock, bond, commodity, or market index. For investors it acts like an insurance policy or a wager: it can be used to protect against losses, lock in prices, or amplify gains and losses, so it can change a portfolio’s risk and potential return without owning the underlying asset directly.
open-market sale financial
"transaction_action": "open-market sale""
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What insider transactions did CGEM’s Chief Scientific Officer report on this Form 4?
Cullinan Therapeutics’ Chief Scientific Officer, Jennifer Michaelson, reported selling 8,000 shares of Common Stock and exercising stock options for 4,000 shares at $4.30 per share, combining an option exercise with open-market sales.
What stock options did Jennifer Michaelson exercise in the CGEM Form 4 filing?
She exercised a Stock Option (Right to Buy) covering 4,000 shares of Cullinan Therapeutics Common Stock at an exercise price of $4.30 per share. This converted a derivative position into additional common shares as part of a broader exercise‑and‑sell pattern.
Was the CGEM insider sale by the Chief Scientific Officer under a Rule 10b5-1 plan?
Yes. A footnote states the transactions were effected pursuant to a Rule 10b5‑1 trading plan established on August 7, 2025. Such pre‑arranged plans automate trades over time, reducing the significance of short‑term timing decisions.
How does this Cullinan Therapeutics (CGEM) Form 4 classify the insider transactions?
The filing classifies the 8,000‑share dispositions as open‑market sales with code S and the 4,000‑share option event as an exercise or conversion of a derivative security with code M. Both positions are reported as direct ownership.
AI-generated analysis. How Rhea-AI works. Not financial advice.
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