X0306 4 2016-12-05 false 0001515673 Ultragenyx Pharmaceutical Inc. RARE 0001598426 Aliski William C/O ULTRAGENYX PHARMACEUTICAL INC. 60 LEVERONI COURT NOVATO CA 94949 true false false false Common Stock 2016-12-05 4 M false 6000.00 21.00 A 65985.00 D Common Stock 2016-12-05 4 S false 4000.00 77.94 D 61985.00 D Common Stock 2016-12-05 4 S false 2000.00 78.70 D 59985.00 D Employee Stock Option (Right to Buy) 21.00 2016-12-05 4 M false 6000.00 0.00 D 2024-01-29 Common Stock 6000.00 11500.00 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $77.60 to $78.51 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $78.60 to $78.75 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. 1/3 of the shares initially subject to the option vested one year from January 30, 2014 and then 1/36 of the shares initially subject to the option began vesting monthly thereafter. /s/ Shalini Sharp by power of attorney for William Aliski 2016-12-05