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: Deykin Aaron (N/A)

Holdings (Derivative)

Security	Exercise Price	Expiration	Underlying	Shares	Ownership
Stock Option (Right to Buy)	$3.45	2032-06-03	Common Stock (279653)		Direct
Stock Option (Right to Buy)	$3.45	2032-06-03	Common Stock (182431)		Direct
Stock Option (Right to Buy)	$4.27	2033-03-02	Common Stock (16258)		Direct
Stock Option (Right to Buy)	$4.87	2033-08-09	Common Stock (11853)		Direct
Stock Option (Right to Buy)	$6.59	2034-05-01	Common Stock (107207)		Direct

Footnotes

F1: 25% of the shares underlying this option vested on April 27, 2023, with the remainder vesting in thirty-six equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.

F2: 25% of the shares underlying this option vested on February 14, 2024, with the remainder vesting in thirty-six equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.

F3: 25% of the shares underlying this option vested on March 3, 2024, with the remainder vesting in thirty-six equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.

F4: 25% of the shares underlying this option vested on August 10, 2024, with the remainder vesting in thirty-six equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.

F5: 25% of the shares underlying this option shall vest on May 2, 2025, with the remainder vesting in thirty-six equal monthly installments thereafter, subject to the Reporting Person's continued service on each such vesting date.