Upstream Bio, Inc. — Director's Dealing 2024

Oct 11, 2024

SEC Form 3 — Initial Statement of Beneficial Ownership

Issuer: Upstream Bio, Inc. (UPB)
CIK: 0002022626
Period of Report: 2024-10-10

Reporting Person: Wellington Biomedical Innovation Master Investors (Cayman) II L.P. (N/A)

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Series B redeemable convertible preferred stock	$		Common Stock (894733)		Direct

Footnotes

F1: Each share of Series B redeemable convertible preferred stock is convertible into Common Stock on a 1.049-for-one basis at the option of the holder, and will convert automatically upon closing of the Issuer's initial public offering into the number of shares shown in column 3 without payment of consideration. The Series B redeemable convertible preferred stock has no expiration date.