Ultragenyx Pharmaceutical Inc.
US ˙ NasdaqGS ˙ US90400D1081

SecurityRARE / Ultragenyx Pharmaceutical Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Sei Investments Co closes position in RARE / Ultragenyx Pharmaceutical Inc.

On May 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 0 shares of Ultragenyx Pharmaceutical Inc. (US:RARE) valued at $0 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 153,726 shares of Ultragenyx Pharmaceutical Inc.. This represents a change in shares of -100.00% during the quarter. The current value of the position is $0 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)
2026-05-13 2026-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -153,726 -100.00 0 -100.00
2026-02-13 2025-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 153,726 -36,736 -19.29 3,536 -38.30 0.0035
2025-11-13 2025-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 190,462 100,270 111.17 5,729 74.72 0.0062
2025-08-14 2025-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 90,192 -22,022 -19.63 3,279 -19.30 0.0038
2025-05-14 2025-03-31 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 112,214 13,905 14.14 4,063 -1.74 0.0052
2025-05-13 2025-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 93,339 -4,970 3,910 0.0043
2025-02-11 2024-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 98,309 -17,828 -15.35 4,136 -35.90 0.0053
2024-11-12 2024-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 116,137 24,338 26.51 6,451 71.02 0.0084
2024-08-13 2024-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 91,799 25,803 39.10 3,773 22.43 0.0053
2024-05-07 2024-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 65,996 616 0.94 3,081 -1.44 0.0045
2024-02-14 2023-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 65,380 9,828 17.69 3,126 57.88 0.0050
2023-11-14 2023-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 55,552 -10,202 -15.52 1,980 -34.72 0.0036
2023-08-11 2023-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 65,754 8,904 15.66 3,033 33.08 0.0053
2023-05-12 2023-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 56,850 -12,256 -17.74 2,280 -28.80 0.0042
2023-02-10 2022-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 69,106 14,199 25.86 3,202 40.77 0.0071
2022-11-14 2022-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 54,907 26,938 96.31 2,274 37.07 0.0051
2022-08-15 2022-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 27,969 1,899 7.28 1,659 -12.27 0.0036
2022-05-13 2022-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 26,070 22,267 585.51 1,891 490.94 0.0038
2022-02-14 2021-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 3,803 3,803 320 0.0006
2021-08-06 2021-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -14,737 -100.00 0 -100.00
2021-05-12 2021-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 14,737 -20 -0.14 1,984 -2.51 0.0050
2021-02-08 2020-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 14,757 -8,303 -36.01 2,035 7.39 0.0053
2020-12-04 2020-09-30 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 23,060 -11,727 -33.71 1,895 -30.36 0.0055
2020-11-06 2020-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 24,066 -10,721 1,978 4,762.5842
2020-08-17 2020-06-30 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 34,787 -4,845 -12.22 2,721 54.51 0.0084
2020-08-11 2020-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 35,090 -4,542 1,499 4,066.1173
2020-05-14 2020-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 39,632 4,542 12.94 1,761 17.48 0.0065
2020-02-06 2019-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 35,090 12,684 56.61 1,499 56.31 0.0045
2019-11-12 2019-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 22,406 -2,280 -9.24 959 -38.84 0.0025
2019-08-14 2019-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 24,686 14,331 138.40 1,568 118.38 0.0051
2019-05-15 2019-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 10,355 10,355 718 0.0024
2018-11-08 2018-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -6 -100.00 0 0.0000
2018-08-03 2018-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 6 -3 -33.33 0 0.0000
2018-05-11 2018-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 9 -2,474 -99.64 0 -100.00
2018-02-08 2017-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,483 454 22.38 115 6.48 0.0004
2017-11-06 2017-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,029 22 1.10 108 -13.60 0.0004
2017-07-31 2017-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,007 2,007 125 0.0005
2017-05-05 2017-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -925 -100.00 0 -100.00
2017-02-02 2016-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 925 -226 -19.64 65 -20.73 0.0003
2016-11-04 2016-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,151 181 18.66 82 74.47 0.0004
2016-08-11 2016-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 970 272 38.97 47 6.82 0.0003
2016-05-10 2016-03-31 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 698 624 843.24 44 388.89 0.0003
2016-02-03 2015-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 74 -20,534 -99.64 9 -99.55 0.0001
2015-11-02 2015-09-30 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 20,608 16,843 447.36 1,985 415.58 0.0182
2015-10-30 2015-09-30 13F DIREXION SHS ETF TR COM 90400D108 20,608 1,985
2015-08-07 2015-06-30 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 3,765 120 3.29 385 70.35 0.0035
2015-08-04 2015-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 3,765 120 385 0.0035
2015-05-14 2015-03-31 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 3,645 3,645 226 0.0020
2015-05-01 2015-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 3,645 226
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.