12/06/2024 - 2Seventy Bio Inc.: Statement of Changes in Beneficial Ownership - Form 4

Ownership Submission

FORM 4 Check this box if no longer subject to Section 16, Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number:3235-0287Expires:January 31, 2005Estimated average burden hours per response...0.5

1. Name and Address of Reporting Person * Casdin Capital, LLC 2. Issuer Name and Ticker or Trading Symbol 2seventy bio, Inc. [TSVT] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 1350 AVENUE OF THE AMERICAS , SUITE 2600 3. Date of Earliest Transaction (Month/Day/Year) (Street) NEW YORK NY 10019 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Join/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code 4. Securities Acquired (A) or Disposed of (D) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) 6. Ownership Form: Direct (D) or Indirect (I) 7. Nature of Indirect Beneficial Ownership Code V Amount (A) or (D) Price

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivate Security	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code	5. Number of Derivative Securities Acquired (A) or Disposed of (D)	6. Date Exercisable and Expiration Date	7. Title and Amount of Securities Underlying Derivative Security	8. Price of Derivative Security	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s)	10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)	11. Nature of Indirect Beneficial Ownership
Code	V	(A)	(D)	Date Exercisable	Expriation Date	Title	Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
Director	10% Owner	Officer	Other
Casdin Capital, LLC 1350 AVENUE OF THE AMERICAS SUITE 2600 NEW YORK, NY10019	X
Casdin Eli 1350 AVENUE OF THE AMERICAS SUITE 2600 NEW YORK, NY10019	X
Casdin Partners Master Fund, L.P. 1350 AVENUE OF THE AMERICAS SUITE 2600 NEW YORK, NY10019	X
Casdin Partners GP, LLC 1350 AVENUE OF THE AMERICAS SUITE 2600 NEW YORK, NY10019	X

Signatures

Casdin Capital LLC, By: /s/ Eli Casdin, Managing Member	2024-06-12
**Signature of Reporting Person	Date
/s/ Eli Casdin, Eli Casdin	2024-06-12
**Signature of Reporting Person	Date
Casdin Partners Master Fund, LP, By: Casdin Partners GP, LLC, its General Partner, By: /s/ Eli Casdin, Managing Member	2024-06-12
**Signature of Reporting Person	Date
Casdin Partners GP LLC, By: /s/ Eli Casdin, Managing Member	2024-06-12
**Signature of Reporting Person	Date

Explanation of Responses:

(*)	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
(**)	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Each restricted stock unit represents the right to receive one share of the Issuer's common Stock, par value $0.0001 per share.
(2)	These shares are comprised of (i) 16,000 restricted stock units that vest ratable over three years in annual installments with the first installment vesting on March 20, 2025, subject to the Reporting Person's continued service through the applicable vesting date and (ii) 6,025 restricted stock units that vest on the earlier of (a) June 10, 2025 or (b) the date of the next annual meeting of stockholders of the Issuer.
(3)	The securities are owned directly by Eli Casdin.
(4)	The securities are owned directly by Casdin Partners Master Fund, L.P. (the "Master Fund") and may be deemed to be indirectly beneficially owned by (i) Casdin Capital, LLC, the investment adviser to the Master Fund ("Casdin"), (ii) Casdin Partners GP, LLC, the general partner of the Master Fund (the "GP"), and (iii) Eli Casdin, the managing member of Casdin and the GP.
(5)	This stock option vests on the earlier of (a) June 10, 2025 or (b) the date of the next annual meeting of stockholders of the Issuer.
(6)	This stock option vests ratably over three years in annual installments with the first installment vesting on March 20, 2025, subject to the Reporting Person's continued service through the applicable vesting date.
(7)	The Master Fund has entered into certain cash-settled total return swap agreements (the "Swap Agreements"), which represent, after the transaction reported herein, economic exposure to an aggregate of 536,784.15 notional shares of the Issuer's Common Stock, par value $0.0001 per share. The Swap Agreements provide the Master Fund with economic results that are comparable to the economic results of ownership but do not provide it with the power to vote or direct the voting or dispose of or direct the disposition of the securities that are referenced by the Swap Agreements.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.

Attachments

• Original Link
• Permalink

Disclaimer

2Seventy Bio Inc. published this content on 12 June 2024 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 12 June 2024 18:35:10 UTC.