UPB Upstream Bio, Inc. Insider Trading

Director Chimovits Erez bought 825,000 shares for $14,025,000.00 at $17.00; part of 2-transaction cluster buy by 3 insiders in 14 days.

Erez, a Director, executed 2 separate purchases totaling 825,000 shares (825.0K shares) for $14,025,000.00 at $17.00 on 2024-10-15, raising his holdings from 3,729,873 shares to 4,554,873 shares (+22.1% net change). This filing is part of a cluster: 2 other insiders also bought within the past 14 days. The company recently listed (5 trading days prior), so post-IPO lockup periods and promotional buying patterns are highly relevant context. Current stock price is $23.60 as of 2024-10-17. The insider holds derivative securities (Form 4 Table II not yet populated in our database), so the Table I holdings do not represent the full position; this is a conversion transaction, not a pure equity purchase.

ORBiMed Advisors (Director) buys 825,000 shares ($14.0M) at $17.00 in 2 transactions; cluster buy pattern observed.

ORBiMed Advisors LLC, a director, executed 2 separate purchases totaling 825,000 shares for $14,025,000.00 on 2024-10-15, increasing holdings from 3,729,873 shares to 4,554,873 shares (+22.1%). The filing coincides with a cluster buy pattern: 2 other insiders also purchased within the past 14 days. The company is in its first 5 trading days post-listing, and the director's acquisition at $17.00 represents a commitment during the critical initial public market phase. Notably, the insider's Table II derivative securities remain not yet populated in the database, so the Table I figure does not reflect the director's total position, warranting deeper scrutiny of the complete holding structure.

AI Upstream LLC (10% Owner) purchases 1,175,000 shares of UPB at $17.00 on 2024-10-15; cluster buy pattern with 2 other insiders in past 14 days post-IPO.

AI Upstream LLC, a 10% shareholder, acquired 1,175,000 shares for $19,975,000.00 on 2024-10-15, five trading days after UPB's recent listing. This purchase increased the insider's position from 4,319,410 shares to 5,494,410 shares, a +27.2% addition. The buy occurs alongside a cluster pattern: 2 other insiders also purchased shares within the past 14 days. In a newly listed company with minimal trading history, multiple insider purchases within a tight window indicate continued inside confidence in the business following public debut. The transaction is a conversion of derivative securities (Form 4 Table II), so this represents a partial exercise/reallocation of existing derivative holdings rather than a discretionary open-market acquisition from outside capital.