AI Upstream LLC - Oct 10, 2024 Form 3 Insider Report for Upstream Bio, Inc. (UPB)

Role: 10%+ Owner
Signature: /s/ Alejandro Moreno for AI Upstream LLC
Stock symbol: UPB
Transactions as of: Oct 10, 2024
Transactions value $: $0
Form type: 3
Date filed: 10/10/2024, 04:27 PM
Next filing: Oct 17, 2024

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	UPB	Series A Preferred Stock							Oct 10, 2024	Common Stock	3M		Direct	F1, F2
holding	UPB	Series B Preferred Stock							Oct 10, 2024	Common Stock	1.12M		Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Each share of Series A preferred stock and Series B preferred stock (collectively, the "Preferred Stock") is currently convertible into Common Stock on a one-for-one basis at the option of the holder, but is expected to be convertible on a 1.049-for-one basis and to be converted automatically upon closing of the Issuer's initial public offering without payment of consideration. The Preferred Stock has no expiration date.
F2	The securities reported are held directly by AI Upstream LLC ("AI Upstream") and may be deemed to be beneficially owned by AI Biotechnology LLC ("AI Biotechnology"), Access Industries Holdings LLC ("AIH"), Access Industries Management, LLC ("AIM") and Len Blavatnik because (i) Mr. Blavatnik controls AIM and AIH, (ii) AIM controls AIH, (iii) AIH owns all of the voting units of AI Biotechnology and (iv) AI Biotechnology owns all of the voting units of AI Upstream. Each of the reporting persons (other than AI Upstream) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this form shall not be construed as an admission that any such reporting person is the beneficial owner of any of the securities reported on this form.

Content

Each share of Series A preferred stock and Series B preferred stock (collectively, the "Preferred Stock") is currently convertible into Common Stock on a one-for-one basis at the option of the holder, but is expected to be convertible on a 1.049-for-one basis and to be converted automatically upon closing of the Issuer's initial public offering without payment of consideration. The Preferred Stock has no expiration date.

The securities reported are held directly by AI Upstream LLC ("AI Upstream") and may be deemed to be beneficially owned by AI Biotechnology LLC ("AI Biotechnology"), Access Industries Holdings LLC ("AIH"), Access Industries Management, LLC ("AIM") and Len Blavatnik because (i) Mr. Blavatnik controls AIM and AIH, (ii) AIM controls AIH, (iii) AIH owns all of the voting units of AI Biotechnology and (iv) AI Biotechnology owns all of the voting units of AI Upstream. Each of the reporting persons (other than AI Upstream) disclaims beneficial ownership of these securities, except to the extent of its or his pecuniary interest therein, and this form shall not be construed as an admission that any such reporting person is the beneficial owner of any of the securities reported on this form.

Remarks:

Exhibit List: Ex.24 - Power of Attorney