13G Filing: Viking Global and Editas Medicine, Inc. (EDIT)

Schedule 13G PAGE 15 of 20

CUSIP No. 28106W103

ITEM 1(a). NAME OF ISSUER:
Editas Medicine, Inc.

ITEM 1(b). ADDRESS OF ISSUER’S PRINCIPAL EXECUTIVE OFFICES:
300 Third Street, First Floor
Cambridge, Massachusetts 02142

ITEM 2(a). NAME OF PERSON FILING:
Viking Global Investors LP (“VGI”),
Viking Global Performance LLC (“VGP”),
Viking Global Equities LP (“VGE”),
Viking Global Equities II LP (“VGEII”),
VGE III Portfolio Ltd. (“VGEIII”),
Viking Long Fund GP LLC (“VLFGP”),
Viking Long Fund Master Ltd. (“VLFM”),
Viking Global Opportunities GP LLC (“Opportunities GP”),
Viking Global Opportunities Portfolio GP LLC
(“Opportunities Portfolio GP”),
Viking Global Opportunities Illiquid Investments Sub-Master LP
(“Opportunities Fund”),
O. Andreas Halvorsen, David C. Ott and
Daniel S. Sundheim (collectively, the “Reporting Persons”)

ITEM 2(b). ADDRESS OF PRINCIPAL OFFICE OR, IF NONE, RESIDENCE:
The business address of each of the Reporting Persons is
55 Railroad Avenue, Greenwich, Connecticut 06830.

ITEM 2(c). CITIZENSHIP:
VGI, VGE and VGEII are Delaware limited partnerships;
VGEIII and VLFM are Cayman Islands exempted companies;
VGP, VLFGP, Opportunities GP and Opportunities Portfolio GP
are Delaware limited liability companies; and Opportunities Fund
is a Cayman Islands exempted limited partnership.
O. Andreas Halvorsen is a citizen of Norway.
David C. Ott and Daniel S. Sundheim are citizens of
the United States.

ITEM 2(d). TITLE OF CLASS OF SECURITIES:
Common Stock (“Common Stock”)

ITEM 2(e). CUSIP NUMBER: 28106W103

ITEM 3. IF THIS STATEMENT IS FILED PURSUANT TO 13d-1(b) OR 13d-2(b) OR (c),
CHECK WHETHER THE PERSON FILING IS A:

(a) [ ] Broker or dealer registered under Section 15 of the
Act

(b) [ ] Bank as defined in Section 3(a)(6) of the Act

(c) [ ] Insurance Company as defined in Section 3(a)(19) of
the Act

(d) [ ] Investment Company registered under Section 8 of the
Investment Company Act of 1940

(e) [ ] Investment Adviser registered under Section 203 of the
Investment Advisers Act of 1940: see Rule 13d-
1(b)(1)(ii)(E)

(f) [ ] Employee Benefit Plan, Pension Fund which is subject
to the provisions of the Employee Retirement Income
Security Act of 1974 or Endowment Fund; see Rule 13d-
1(b)(1)(ii)(F)