| Type | Filed | Filer | Subject | Shares Owned | Percent Owned | |
|---|---|---|---|---|---|---|
| SC 13D/A | 2014-12-11 | BAKER BROS. ADVISORS LP | SEATTLE GENETICS INC /WA | 25,086,092 | 20.2% | EDGAR |
| SC 13D/A | 2014-11-12 | BAKER BROS. ADVISORS LP | SEATTLE GENETICS INC /WA | 24,237,404 | 19.5% | EDGAR |
| SC 13G/A | 2014-10-08 | BlackRock Inc. | SEATTLE GENETICS INC /WA | 6,093,332 | 4.9% | EDGAR |
| SC 13D/A | 2014-05-16 | BAKER BROS. ADVISORS LP | SEATTLE GENETICS INC /WA | 21,538,669 | 17.5% | EDGAR |
| SC 13D/A | 2014-05-12 | BAKER BROS. ADVISORS LP | SEATTLE GENETICS INC /WA | 21,349,058 | 17.3% | EDGAR |
| SC 13G/A | 2014-02-14 | FMR LLC | SEATTLE GENETICS INC /WA | 18,376,030 | 15.0% | EDGAR |
| SC 13G/A | 2014-02-14 | WELLINGTON MANAGEMENT CO LLP | SEATTLE GENETICS INC /WA | 2,987,124 | 2.4% | EDGAR |
| SC 13G/A | 2014-02-14 | PRIMECAP MANAGEMENT CO/CA/ | SEATTLE GENETICS INC /WA | 10,523,157 | 8.9% | EDGAR |
| SC 13G | 2014-02-11 | VANGUARD GROUP INC | SEATTLE GENETICS INC /WA | 6,513,889 | 5.3% | EDGAR |
| SC 13G/A | 2014-02-07 | CAPITAL GROUP INTERNATIONAL INC | SEATTLE GENETICS INC /WA | 7,536,078 | 6.1% | EDGAR |
| SC 13G | 2014-02-06 | COLUMBIA WANGER ASSET MANAGEMENT LLC | SEATTLE GENETICS INC /WA | 6,701,000 | 5.4% | EDGAR |
| SC 13G/A | 2014-01-30 | BlackRock Inc. | SEATTLE GENETICS INC /WA | 7,371,957 | 6.0% | EDGAR |
| SC 13G/A | 2014-01-10 | BAILLIE GIFFORD & CO | SEATTLE GENETICS INC /WA | 13,315,804 | 10.9% | EDGAR |
| SC 13D/A | 2013-12-17 | BAKER BROS. ADVISORS LP | SEATTLE GENETICS INC /WA | 20,735,926 | 16.9% | EDGAR |
| SC 13G | 2013-12-06 | BAILLIE GIFFORD & CO | SEATTLE GENETICS INC /WA | 13,379,504 | 10.9% | EDGAR |
| SC 13D/A | 2013-07-11 | BAKER JULIAN | SEATTLE GENETICS INC /WA | 19,322,947 | 16.1% | EDGAR |
| SC 13G/A | 2013-02-14 | FMR LLC | SEATTLE GENETICS INC /WA | 16,072,490 | 13.5% | EDGAR |
| SC 13G/A | 2013-02-14 | WELLINGTON MANAGEMENT CO LLP | SEATTLE GENETICS INC /WA | 6,445,082 | 5.4% | EDGAR |
| SC 13G/A | 2013-02-14 | PRIMECAP MANAGEMENT CO/CA/ | SEATTLE GENETICS INC /WA | 10,523,157 | 8.8% | EDGAR |
| SC 13G/A | 2013-02-14 | COLUMBIA WANGER ASSET MANAGEMENT LLC | SEATTLE GENETICS INC /WA | 8,965,304 | 7.5% | EDGAR |