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* G1 EXECUTION SERVICES, LLC (Last) (First) (Middle) 175 W. JACKSON BLVD., SUITE 1700 501 PLAZA 2 (Street) CHICAGO IL 60604 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol ACHILLION PHARMACEUTICALS INC [ ACHN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 01/28/2020
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X 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	01/28/2020		J(1)		10,917	D	$6.3(1)	0	D(2)(4)
Common Stock	01/28/2020		J(1)		14,115,498	D	$6.3(1)	0	D(3)(4)

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

1. Name and Address of Reporting Person* G1 EXECUTION SERVICES, LLC (Last) (First) (Middle) 175 W. JACKSON BLVD., SUITE 1700 501 PLAZA 2 (Street) CHICAGO IL 60604 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC (Last) (First) (Middle) 401 CITY AVENUE, SUITE 220 (Street) BALA CYNWYD PA 19004 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* SUSQUEHANNA SECURITIES, LLC (Last) (First) (Middle) 401 CITY AVENUE, SUITE 220 (Street) BALA CYNWYD PA 19004 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. Disposed of pursuant to an Agreement and Plan of Merger among Achillion Pharmaceuticals, Inc., Alexion Pharmaceuticals, Inc. and Beagle Merger Sub, Inc. In addition to the cash consideration of $6.30 per share, each shareholder will also receive one contingent value right ("CVR") per share. Each CVR represents the right to receive contingent cash payments of $1.00 upon the achievement of a certain clinical trial milestone with respect to ACH-5228 and $1.00 upon the achievement of a certain regulatory approval milestone with respect to ACH-4471.

2. These securities are directly owned by G1 Execution Services, LLC ("G1X").

3. These securities are directly owned by Susquehanna Securities, LLC ("SS").

4. G1X, Susquehanna Fundamental Investments, LLC ("SFNDI") and SS are affiliated entities under common ownership. G1X, SFNDI and SS each disclaim beneficial ownership of the reported securities except to the extent of their respective pecuniary interest therein, and this report shall not be deemed an admission that any of them are the beneficial owners of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

	G1 Execution Services, LLC By: /s/ Brian Sopinsky Name: Brian Sopinsky Title: Secretary	01/30/2020
	Susquehanna Fundamental Investments, LLC By: /s/ Brian Sopinsky Name: Brian Sopinsky Title: Assistant Secretary	01/30/2020
	Susquehanna Securities, LLC By: /s/ Brian Sopinsky Name: Brian Sopinsky Title: Secretary	01/30/2020
	** 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).
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