Ownership Profile

Top Holders

Holder Shares Held % O/S Share Change Filing Date
Fidelity Management & Research Company 20,455,239 14.87 1,635,782 9/30/18
Biogen Idec Inc 11,501,153 8.36 11,501,153 6/5/18
The Vanguard Group, Inc. 11,091,298 8.06 157,770 9/30/18
ClearBridge Investments, LLC 10,236,939 7.44 -583,181 9/30/18
Wellington Management Company, LLP 9,295,165 6.76 46,804 9/30/18
Bellevue Asset Management AG 8,976,870 6.53 -12,050 9/30/18
Baillie Gifford & Co. 8,750,014 6.36 -208,099 12/31/18
BlackRock Institutional Trust Company, N.A. 6,874,916 5.00 402,129 9/30/18
Ivy Investments 3,894,337 2.83 61,936 11/30/18
Waddell & Reed Investment Management Company 3,832,711 2.79 -697,389 9/30/18

Top Holders: Mutual Funds

Fund Shares Held % O/S Share Change Filing Date
BB Biotech Fd 8,666,334 6.30 -- 9/30/18
Fidelity Growth Company Fund 7,996,092 5.81 -10,734 11/30/18
Ivy Science and Technology Fund 3,534,001 2.57 -645,999 9/30/18
Vanguard Total Stock Market Index Fund 3,295,568 2.40 137,408 12/31/18
Vanguard Small-Cap Index Fund 3,180,326 2.31 25,005 12/31/18
ClearBridge Aggressive Growth Fund 2,722,745 1.98 -- 9/30/18
Fidelity Select Biotechnology Portfolio 2,524,877 1.84 -- 11/30/18
Hartford MidCap Fund 2,339,157 1.70 -663,801 11/30/18
Fidelity Series Growth Company Fund 2,148,379 1.56 -38,406 11/30/18
Vanguard Health Care Fund 2,119,180 1.54 -- 9/30/18

* Insider values reflect direct beneficial ownership.

Copyright Thomson Reuters Corporation

©1999 - 2017 Ionis Pharmaceuticals™ is a trademark of Ionis Pharmaceuticals, Inc. Akcea Therapeutics™ is a trademark of Ionis Pharmaceuticals, Inc.