| 5.20% | % of Shares Held by All Insider |
| 101.40% | % of Shares Held by Institutions |
| 106.96% | % of Float Held by Institutions |
| 194 | Number of Institutions Holding Shares |
| Holder | Shares | Date Reported | % Out | Value |
|---|---|---|---|---|
| Price (T.Rowe) Associates Inc | 7,712,078 | Dec 30, 2018 | 11.26% | 79,048,799 |
| Redmile Group, LLC | 6,505,766 | Dec 30, 2018 | 9.50% | 66,684,101 |
| Vanguard Group, Inc. (The) | 5,265,230 | Dec 30, 2018 | 7.69% | 53,968,607 |
| Blackrock Inc. | 4,934,624 | Dec 30, 2018 | 7.20% | 50,579,896 |
| Wellington Management Company, LLP | 4,765,123 | Dec 30, 2018 | 6.96% | 48,842,510 |
| Foresite Capital Management III, LLC | 2,942,130 | Dec 30, 2018 | 4.30% | 30,156,832 |
| State Street Corporation | 2,830,135 | Dec 30, 2018 | 4.13% | 29,008,883 |
| Samlyn Capital, LLC | 2,818,788 | Dec 30, 2018 | 4.12% | 28,892,577 |
| BB Biotech Ag | 2,766,008 | Dec 30, 2018 | 4.04% | 28,351,582 |
| Goldman Sachs Group, Inc. | 2,762,172 | Dec 30, 2018 | 4.03% | 28,312,263 |
| Holder | Shares | Date Reported | % Out | Value |
|---|---|---|---|---|
| Price (T.Rowe) Health Sciences Fund | 2,580,148 | Dec 30, 2018 | 3.77% | 26,446,517 |
| SPDR (R) Ser Tr-SPDR (R) S&P (R) Biotech ETF | 1,727,096 | Feb 27, 2019 | 2.52% | 22,141,370 |
| Vanguard Small-Cap Index Fund | 1,476,967 | Sep 29, 2018 | 2.16% | 24,591,500 |
| Vanguard Total Stock Market Index Fund | 1,475,304 | Sep 29, 2018 | 2.15% | 24,563,811 |
| Price (T.Rowe) Small Cap Stock Fund | 1,272,600 | Dec 30, 2018 | 1.86% | 13,044,150 |
| iShares Russell 2000 ETF | 1,237,274 | Feb 27, 2019 | 1.81% | 15,861,852 |
| Fidelity Small Cap Growth Fund | 1,027,620 | Jan 30, 2019 | 1.50% | 14,468,889 |
| College Retirement Equities Fund-Stock Account | 1,014,969 | Sep 29, 2018 | 1.48% | 16,899,233 |
| Goldman Sachs Tr-Goldman Sachs Small/Mid Cap Growth Fund | 897,944 | Aug 30, 2018 | 1.31% | 16,252,786 |
| Price (T.Rowe) Institutional Small-Cap Stock Fund | 876,045 | Mar 30, 2019 | 1.28% | 11,958,014 |