SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP 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: 3235-0287 Estimated average burden hours per response: 0.5
X	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* LYNCH DANIEL (Last) (First) (Middle) 60 BINNEY STREET (Street) CAMBRIDGE, MA 02142 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol bluebird bio, Inc. [ BLUE ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 11/11/2021
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock(1)(2)(3)	11/11/2021		J		0	A	$0	7,959	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	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 (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	$2.74(4)	11/11/2021		J			23,342(4)	(4)	01/16/2023	Common Stock	22,981	$0	22,981	D
Stock Option (right to buy)	$12.54(5)	11/11/2021		J			10,500(5)	(5)	06/11/2024	Common Stock	10,337	$0	10,337	D
Stock Option (right to buy)	$92.14(6)	11/11/2021		J			10,500(6)	(6)	06/04/2025	Common Stock	10,337	$0	10,337	D
Stock Option (right to buy)	$23.85(7)	11/11/2021		J			5,600(7)	(7)	06/02/2026	Common Stock	5,513	$0	5,513	D
Stock Option (right to buy)	$55.29(8)	11/11/2021		J			5,600(8)	(8)	06/08/2027	Common Stock	5,513	$0	5,513	D
Stock Option (right to buy)	$91.2(9)	11/11/2021		J			5,600(9)	(9)	06/20/2028	Common Stock	5,513	$0	5,513	D
Stock Option (right to buy)	$60.78(10)	11/11/2021		J			5,600(10)	(10)	06/06/2029	Common Stock	5,513	$0	5,513	D
Stock Option (right to buy)	$31.93(11)	11/11/2021		J			4,200(11)	(11)	06/18/2030	Common Stock	4,135	$0	4,135	D
Stock Option (right to buy)	$0.0(12)	11/11/2021		J			7,000(12)	(12)	06/15/2031	Common Stock	0.0	$0	0	D

Explanation of Responses:

1. Represents restricted stock units awarded to the reporting person prior to the separation (the "Separation") of 2seventy bio, Inc. ("2seventy") from bluebird bio, Inc. ("bluebird"). In connection with the Separation, the restricted stock units underlying this award were adjusted pursuant to the the Employee Matters Agreement by and between 2seventy and bluebird (the "EMA") to preserve the value associated with the original restricted stock unit award (see footnotes 2 and 3). This restricted stock unit award was originally granted on June 15, 2021 and vests 100% on the earlier of June 15, 2022 or the date of the next annual meeting of stockholders.

2. bluebird equity awards granted prior to January 1, 2021 were converted into equity awards of both bluebird and 2seventy. The number of shares underlying the converted bluebird equity awards was determined by multiplying the number of shares underlying the existing bluebird equity award by a fraction, the numerator of which is the volume-weighted average trading price of bluebird common stock (trading "regular way") on the five trading days immediately prior to the distribution date (the "bluebird Pre-Distribution VWAP") and the denominator of which is the sum of (1) the volume-weighted average trading price of 2seventy common stock (trading "regular way") on the five trading days immediately following the distribution date multiplied by the distribution ratio and (2) the volume-weighted average trading price of bluebird bio common stock (trading "regular way") on the five trading days immediately following the distribution date (the "bluebird Post-Distribution VWAP").

3. bluebird equity awards granted on or after January 1, 2021, such equity awards continued as bluebird equity awards, subject to adjustment. The adjusted number of shares of bluebird common stock underlying such equity awards is equal to the number of shares of bluebird common stock subject to the equity award immediately prior to the distribution multiplied by a fraction, the numerator of which is the bluebird Pre-Distribution VWAP and the denominator of which is the bluebird Post-Distribution VWAP.

4. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on January 16, 2013 and is fully vested and exercisable as of the date hereof. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

5. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on June 11, 2014 and is fully vested and exercisable as of the date hereof. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

6. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on June 4, 2015 and is fully vested and exercisable as of the date hereof. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

7. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on June 2, 2016 and is fully vested and exercisable as of the date hereof. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

8. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on June 8, 2017 and is fully vested and exercisable as of the date hereof. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

9. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on June 20, 2018 and is fully vested and exercisable as of the date hereof. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

10. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on June 6, 2019 and is fully vested and exercisable as of the date hereof. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

11. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on June 18, 2020 and is fully vested and exercisable as of the date hereof. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

12. Represents options to purchase bluebird common stock awarded to the reporting person prior to the Separation. . In connection with the Separation, the shares of common stock underlying this award were adjusted pursuant to the EMA such that the reporting person received options to purchase shares of 2seventy common stock to preserve the value associated with the original award (see footnotes 2 and 3). This option was originally granted on June 15, 2021 and shall vest 100% on the earlier of June 15, 2022 or the date of the next annual meeting of the stockholders. The exercise price of the option has been adjusted based on the conversion ratio described in footnotes 2 and 3.

Remarks:

	/s/ Helen Fu, Attorney-in-Fact	11/17/2021
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.