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. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Finer Mitchell H.
   2. Issuer Name and Ticker or Trading Symbol
bluebird bio, Inc. [BLUE] 		5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Scientific Officer
(Last)
(First)
(Middle)
C/O BLUEBIRD BIO, INC., 150 SECOND STREET		 3. Date of Earliest Transaction (Month/Day/Year)
04/20/2015
(Street)

CAMBRIDGE, MA 02141		 4. If Amendment, Date 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
(City)
(State)
(Zip)
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 04/20/2015   M   1,166 A $ 2.0864 1,166 D  
Common Stock 04/20/2015   M   13,834 A $ 5.5004 15,000 D  
Common Stock 04/20/2015   S(1)   2,520 D $ 123.5253 (2) 12,480 D  
Common Stock 04/20/2015   S(1)   1,689 D $ 124.706 (3) 10,791 D  
Common Stock 04/20/2015   S(1)   5,457 D $ 125.6223 (4) 5,334 D  
Common Stock 04/20/2015   S(1)   750 D $ 126.6818 (5) 4,584 D  
Common Stock 04/20/2015   S(1)   3,875 D $ 127.8359 (6) 709 D  
Common Stock 04/20/2015   S(1)   11 D $ 128.25 698 D  
Common Stock 04/20/2015   S(1)   628 D $ 130.5741 (7) 70 D  
Common Stock 04/20/2015   S(1)   70 D $ 131.29 (8) 0 D  

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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 Underlying Securities
(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 of Derivative Security: 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) $ 2.0864 04/20/2015   M     900   (9) 07/13/2021 Common Stock 900 $ 0 0 D  
Stock Option (right to buy) $ 2.0864 04/20/2015   M     266   (9) 07/13/2021 Common Stock 266 $ 0 0 D  
Stock Option (right to buy) $ 5.5004 04/20/2015   M     8,384   (10) 01/16/2023 Common Stock 8,384 $ 0 30,371 D  
Stock Option (right to buy) $ 5.5004 04/20/2015   M     5,450   (11) 01/16/2023 Common Stock 5,450 $ 0 114,364 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Finer Mitchell H.
C/O BLUEBIRD BIO, INC.
150 SECOND STREET
CAMBRIDGE, MA 02141		       Chief Scientific Officer  

Signatures

 /s/ Eric Sullivan, Attorney-in-Fact   04/22/2015
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 22, 2014.
(2) The range of prices for the transaction reported on this line was $123.14 to $124.08. The average weighted price was $123.5253. The reporting person will provide, upon request by the SEC, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
(3) The range of prices for the transaction reported on this line was $124.15 to $125.10. The average weighted price was $124.7060. The reporting person will provide, upon request by the SEC, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
(4) The range of prices for the transaction reported on this line was $125.21 to $126.18. The average weighted price was $125.6223. The reporting person will provide, upon request by the SEC, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
(5) The range of prices for the transaction reported on this line was $126.23 to $126.92. The average weighted price was $126.6818. The reporting person will provide, upon request by the SEC, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
(6) The range of prices for the transaction reported on this line was $127.2350 to $128.20. The average weighted price was $127.8359. The reporting person will provide, upon request by the SEC, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
(7) The range of prices for the transaction reported on this line was $130.00 to $131.00. The average weighted price was $130.5741. The reporting person will provide, upon request by the SEC, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
(8) The range of prices for the transaction reported on this line was $131.25 to $131.35. The average weighted price was $131.29. The reporting person will provide, upon request by the SEC, the issuer or a security holder of the issuer, full information regarding the number of shares sold at each separate price.
(9) This option vests at a rate of twenty-five percent (25%) on April 15, 2012 and in 36 equal monthly installments thereafter.
(10) This option to purchase shares of our common stock granted on January 16, 2013 with performance-based vesting criteria that were met as of January 1, 2013. The shares underlying these options vested as follows: 25% vested on January 1, 2014, with the remainder of the shares vesting in equal monthly installments over the following three years.
(11) This option to purchase shares of our common stock granted on January 16, 2013 with performance-based vesting criteria that were met as of May 1, 2013. The shares underlying these options vested as follows: 25% vested on May 1, 2014, with the remainder of the shares vesting in equal monthly installments over the following three years.

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