2Seventy Bio Inc.

03/28/2024 | Press release | Distributed by Public on 03/28/2024 18:30

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
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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 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

Casdin Eli
1350 AVENUE OF THE AMERICAS
SUITE 2600
NEW YORK, NY10019 		X

Signatures

Casdin Capital LLC, By: /s/ Eli Casdin, Managing Member 2024-03-28
**Signature of Reporting Person Date
Casdin Partners Master Fund, LP, By: Casdin Partners GP, LLC, its General Partner, By: /s/ Eli Casdin, Managing Member 2024-03-28
**Signature of Reporting Person Date
Casdin Partners GP LLC, By: /s/ Eli Casdin, Managing Member 2024-03-28
**Signature of Reporting Person Date
/s/ Eli Casdin, Eli Casdin 2024-03-28
**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) The price reported in Column 4 is a weighted average price. These shares were bought in multiple transactions within the range of $4.9 to $5.41. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares bought at each separate price within the range set forth in this footnote.
(2) 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.
(3) This restricted stock unit award vests 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.
(4) The securities are owned directly by Eli Casdin.
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.