Ultragenyx Pharmaceutical Inc.
US ˙ NasdaqGS ˙ US90400D1081

SecurityRARE / Ultragenyx Pharmaceutical Inc.
InstitutionState Street Corp
Latest Disclosed Ownership5,021,441 shares
Latest Disclosed Value $ 105,199,189
State Street Corp reports 16.70% increase in ownership of RARE / Ultragenyx Pharmaceutical Inc.

On May 15, 2026 - State Street Corp filed a 13F-HR form disclosing ownership of 5,021,441 shares of Ultragenyx Pharmaceutical Inc. (US:RARE) valued at $105,199,189 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 4,303,046 shares of Ultragenyx Pharmaceutical Inc.. This represents a change in shares of 16.70% during the quarter. The current value of the position is $110,019,772 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 5,021,441 718,395 16.70 105,199 6.29 0.0036
2026-02-13 2025-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 4,303,046 610,559 16.54 98,970 -10.89 0.0033
2025-11-14 2025-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 3,692,487 1,120,247 43.55 111,070 18.76 0.0039
2025-08-14 2025-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,572,240 -46,250 -1.77 93,527 -1.36 0.0035
2025-05-15 2025-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,618,490 -104,134 -3.82 94,816 -17.22 0.0039
2025-02-14 2024-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,722,624 58,547 2.20 114,541 -22.60 0.0045
2024-11-14 2024-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,664,077 -33,024 -1.22 147,989 33.50 0.0060
2024-08-14 2024-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,697,101 -154,149 -5.41 110,851 -16.73 0.0048
2024-05-15 2024-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,851,250 -401,252 -12.34 133,125 -14.41 0.0060
2024-02-14 2023-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 3,252,502 684,644 26.66 155,535 69.90 0.0076
2023-11-14 2023-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,567,858 102,408 4.15 91,544 -19.51 0.0051
2023-08-14 2023-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,465,450 -280,257 -10.21 113,731 3.30 0.0060
2023-05-15 2023-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,745,707 -197,060 -6.70 110,103 -19.24 0.0062
2023-05-15 2022-12-31 13F/A-99 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,942,767 383,223 14.97 136,338 28.63 0.0080
2023-05-15 2022-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,942,767 383,223 136,338 0.0080
2022-11-15 2022-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,559,544 102,236 4.16 105,991 -27.70 0.0067
2022-08-15 2022-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,457,308 508,624 26.10 146,603 3.60 0.0088
2022-05-16 2022-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,948,684 269,843 16.07 141,513 0.24 0.0070
2022-02-14 2021-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,678,841 204,976 13.91 141,174 6.20 0.0067
2021-11-15 2021-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,473,865 102,990 7.51 132,928 1.69 0.0070
2021-08-16 2021-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,370,875 -239,964 -14.90 130,713 -28.73 0.0069
2021-07-09 2021-03-31 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,610,839 -65,460 -3.91 183,410 -20.96 0.0105
2021-05-17 2021-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,610,839 -65,460 183,410 0.0105
2021-02-16 2020-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,676,299 -140,693 -7.74 232,050 55.38 0.0142
2020-11-10 2020-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,816,992 -161,252 -8.15 149,339 -3.49 0.0102
2020-08-14 2020-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,978,244 -251,107 -11.26 154,738 56.22 0.0112
2020-06-19 2020-03-31 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,229,351 30,604 1.39 99,050 5.48 0.0087
2020-05-11 2020-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,229,351 30,604 99,050 8,698.5844
2020-02-06 2019-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,198,747 87,859 4.16 93,908 3.99 0.0064
2019-11-14 2019-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,110,888 -8,844 -0.42 90,304 -32.91 0.0067
2019-08-14 2019-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,119,732 198,021 10.30 134,603 0.99 0.0100
2019-05-15 2019-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,921,711 -129,928 -6.33 133,290 49.42 0.0104
2019-02-12 2018-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,051,639 339,115 19.80 89,205 -31.77 0.0081
2018-11-09 2018-09-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,712,524 63,773 3.87 130,735 3.16 0.0100
2018-08-14 2018-06-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,648,751 -368,544 -18.27 126,736 23.21 0.0106
2018-05-15 2018-03-31 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 2,017,295 420,776 26.36 102,864 38.91 0.0087
2018-02-14 2017-12-31 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,596,519 81,448 5.38 74,050 -8.23 0.0060
2017-11-14 2017-09-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,515,071 -21,214 -1.38 80,689 -15.44 0.0070
2017-08-14 2017-06-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,536,285 270,729 21.39 95,417 11.23 0.0084
2017-05-15 2017-03-31 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,265,556 -131,633 -9.42 85,784 -12.67 0.0077
2017-02-09 2016-12-31 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,397,189 -80,247 -5.43 98,227 -6.28 0.0092
2017-01-13 2016-09-30 13F/A-1 ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,477,436 208,750 16.45 104,807 68.91 0.0106
2016-11-14 2016-09-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,477,436 104,807
2016-08-12 2016-06-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,268,686 -15,638 -1.22 62,048 -23.69 0.0067
2016-05-20 2016-03-31 13F/A-1 ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,284,324 300,901 30.60 81,315 -26.29 0.0088
2016-05-12 2016-03-31 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 1,284,324 81,315
2016-02-16 2015-12-31 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 983,423 126,542 14.77 110,321 33.68 0.0121
2015-11-16 2015-09-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 856,881 19,831 2.37 82,525 -3.71 0.0096
2015-08-13 2015-06-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 837,050 317,063 60.98 85,705 165.46 0.0092
2015-05-15 2015-03-31 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 519,987 -5,794 -1.10 32,285 39.93 0.0033
2015-02-11 2014-12-31 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 525,781 146,916 38.78 23,072 7.59 0.0023
2014-11-12 2014-09-30 13F/A-1 ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 378,865 286,995 312.39 21,445 420.51 0.0023
2014-11-10 2014-09-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 378,865 21,445
2014-08-12 2014-06-30 13F ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 91,870 27,889 43.59 4,120 31.59 0.0004
2014-05-15 2014-03-31 13F/A-1 ULTRAGENYX PHARMACEUTICAL Common equity shares 90400D108 63,981 63,981 3,131 0.0004
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.