Ultragenyx Pharmaceutical Inc.
US ˙ NasdaqGS ˙ US90400D1081

SecurityRARE / Ultragenyx Pharmaceutical Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership4,729 shares
Latest Disclosed Value $ 99,072
Simplex Trading, Llc ownership in RARE / Ultragenyx Pharmaceutical Inc.

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 4,729 shares of Ultragenyx Pharmaceutical Inc. (US:RARE) valued at $99,073 USD as of March 31, 2026. The entity filed a previous 13F-HR on August 5, 2025 disclosing 0 shares of Ultragenyx Pharmaceutical Inc.. The current value of the position is $105,977 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (RARE) in the form of stock options. The firm currently holds call options representing 15,500 of underlying shares valued at $324,725 USD and put options representing 9,400 of underlying shares valued at $196,930 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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.

Upgrade to unlock premium data and export to Excel .

Institutional Put/Call Ratios
(Premium Subscription Required)

In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

RARE / Ultragenyx Pharmaceutical Inc. Historical Put/Call Ratio
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)
2026-05-14 2026-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 4,729 4,729 99 0.0001
2025-08-05 2025-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -23,991 -100.00 0 0.0000
2025-05-12 2025-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 23,991 18,062 304.64 1 0.0006
2025-02-11 2024-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 5,929 -4,418 -42.70 0 0.0001
2024-11-08 2024-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 10,347 5,512 114.00 1 0.0003
2024-07-25 2024-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 4,835 3,881 406.81 0 0.0001
2024-04-25 2024-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 954 954 0 0.0000
2022-05-02 2022-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -94 -100.00 0 -100.00
2022-02-23 2021-12-31 13F/A-1 ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 94 -24 -20.34 7 -36.36 0.0000
2022-02-04 2021-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 118 0 11 0.0000
2021-10-28 2021-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 118 0 0.00 11 0.00 0.0000
2021-08-12 2021-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 118 -282 -70.50 11 -75.56 0.0000
2021-04-26 2021-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 400 400 238.98 45 309.09 0.0001
2020-10-14 2020-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -23,579 -100.00 0 -100.00
2020-07-13 2020-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 23,579 8,294 54.26 1,844 171.58 0.0029
2020-04-29 2020-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 15,285 2,513 19.68 679 24.59 0.0012
2020-02-05 2019-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 12,772 1,659 14.93 545 14.74 0.0012
2019-10-15 2019-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 11,113 11,113 -12.99 475 -12.84 0.0014
2019-07-26 2019-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -3,593 -100.00 0 -100.00
2019-04-18 2019-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 3,593 3,593 249 0.0007
2019-01-16 2018-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -831 -100.00 0 -100.00
2018-10-23 2018-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 831 831 63 0.0002
2018-07-30 2018-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -2,696 -100.00 0 -100.00
2018-04-26 2018-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,696 2,696 137 0.0060
2017-10-25 2017-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 0 -1,441 -100.00 0 -100.00
2017-07-12 2017-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,441 -6,457 -81.75 89 -83.36 0.0039
2017-04-21 2017-03-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 7,898 700 9.72 535 5.73 0.0232
2017-01-11 2016-12-31 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 7,198 4,580 174.94 506 173.51 0.0302
2016-10-07 2016-09-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 2,618 1,451 124.34 185 224.56 0.0125
2016-07-18 2016-06-30 13F ULTRAGENYX PHARMACEUTICAL IN COM 90400D108 1,167 1,167 57 0.0038
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-14 2026-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 15,500 325 n/a n/a n/a
2026-02-11 2025-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-12 2025-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 64,500 -42.87 2 -75.00 n/a n/a n/a
2025-08-05 2025-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 112,900 144.37 4 300.00 n/a n/a n/a
2025-05-12 2025-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 46,200 470.37 2 n/a n/a n/a
2025-02-11 2024-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 8,100 15.71 0 n/a n/a n/a
2024-11-08 2024-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 7,000 -51.72 0 n/a n/a n/a
2024-07-25 2024-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 14,500 -47.08 1 -100.00 n/a n/a n/a
2024-04-25 2024-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 27,400 20.18 1 0.00 n/a n/a n/a
2024-02-02 2023-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 22,800 -51.18 1 0.00 n/a n/a n/a
2023-11-01 2023-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 46,700 19.44 2 0.00 n/a n/a n/a
2023-08-04 2023-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 39,100 88.89 2 n/a n/a n/a
2023-04-27 2023-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 20,700 187.50 1 n/a n/a n/a
2023-02-02 2022-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 7,200 -41.46 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 12,300 4,000.00 509 2,894.12 n/a n/a n/a
2022-08-03 2022-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 300 50.00 17 21.43 n/a n/a n/a
2022-05-02 2022-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 200 -66.67 14 -75.00 n/a n/a n/a
2022-02-04 2021-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 600 0.00 56 0.00 n/a n/a n/a
2021-10-28 2021-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 600 0.00 56 -1.75 n/a n/a n/a
2021-08-12 2021-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 600 482.52 57 -95.14 n/a n/a n/a
2021-04-26 2021-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 103 -4.63 1,172 -21.61 n/a n/a n/a
2021-02-02 2020-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 108 5,300.00 1,495 9,243.75 n/a n/a n/a
2020-10-14 2020-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 2 -96.67 16 -96.59 n/a n/a n/a
2020-07-13 2020-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 60 81.82 469 221.23 n/a n/a n/a
2020-04-29 2020-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 33 -38.89 146 -36.52 n/a n/a n/a
2020-02-05 2019-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 54 980.00 230 995.24 n/a n/a n/a
2019-10-15 2019-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 5 -44.44 21 -63.16 n/a n/a n/a
2019-07-26 2019-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 9 28.57 57 18.75 n/a n/a n/a
2019-04-18 2019-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 7 -22.22 48 -15.79 n/a n/a n/a
2019-01-16 2018-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-10-23 2018-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 15 0.00 114 -0.87 n/a n/a n/a
2018-07-30 2018-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 15 25.00 115 666.67 n/a n/a n/a
2018-04-26 2018-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 12 -25.00 15 650.00 n/a n/a n/a
2018-01-10 2017-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 16 -88.97 2 -87.50 n/a n/a n/a
2017-10-25 2017-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 145 52.63 16 -5.88 n/a n/a n/a
2017-07-12 2017-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 95 -3.06 17 6.25 n/a n/a n/a
2017-04-21 2017-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 98 81.48 16 -11.11 n/a n/a n/a
2017-01-11 2016-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 54 575.00 18 157.14 n/a n/a n/a
2016-10-07 2016-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 8 -82.22 7 600.00 n/a n/a n/a
2016-07-18 2016-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 45 55.17 1 0.00 n/a n/a n/a
2016-04-14 2016-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 29 16.00 1 -94.44 n/a n/a n/a
2016-01-20 2015-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 25 -35.90 18 0.00 n/a n/a n/a
2015-10-08 2015-09-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 39 -13.33 18 -79.78 n/a n/a n/a
2015-07-08 2015-06-30 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 45 650.00 89 2,866.67 n/a n/a n/a
2015-04-21 2015-03-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 6 20.00 3 -96.63 n/a n/a n/a
2015-03-04 2014-12-31 13F ULTRAGENYX PHARMACEUTICAL IN CALL Call 5 0 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-14 2026-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 9,400 197 n/a n/a n/a
2026-02-11 2025-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 0 -100.00 0 n/a n/a n/a
2025-11-12 2025-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 23,400 -81.65 1 -100.00 n/a n/a n/a
2025-08-05 2025-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 127,500 218.75 5 300.00 n/a n/a n/a
2025-05-12 2025-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 40,000 191.97 1 n/a n/a n/a
2025-02-11 2024-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 13,700 37.00 1 n/a n/a n/a
2024-11-08 2024-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 10,000 12.36 1 n/a n/a n/a
2024-07-25 2024-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 8,900 97.78 0 n/a n/a n/a
2024-04-25 2024-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 4,500 -4.26 0 n/a n/a n/a
2024-02-02 2023-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 4,700 -54.37 0 n/a n/a n/a
2023-11-01 2023-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 10,300 178.38 0 n/a n/a n/a
2023-08-04 2023-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 3,700 15.62 0 n/a n/a n/a
2023-04-27 2023-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 3,200 190.91 0 n/a n/a n/a
2023-02-02 2022-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 1,100 -86.25 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 8,000 2,566.67 331 1,847.06 n/a n/a n/a
2022-08-03 2022-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 300 -86.96 17 -89.82 n/a n/a n/a
2022-05-02 2022-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 2,300 228.57 167 187.93 n/a n/a n/a
2022-02-23 2021-12-31 13F/A ULTRAGENYX PHARMACEUTICAL IN PUT Put 700 58 n/a n/a n/a
2021-08-12 2021-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-04-26 2021-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 1 11 n/a n/a n/a
2021-02-02 2020-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-10-14 2020-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 1 -99.53 8 -99.52 n/a n/a n/a
2020-07-13 2020-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 213 191.78 1,666 414.20 n/a n/a n/a
2020-04-29 2020-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 73 -82.58 324 -81.89 n/a n/a n/a
2020-02-05 2019-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 419 94.88 1,789 94.67 n/a n/a n/a
2019-10-15 2019-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 215 1,435.71 919 944.32 n/a n/a n/a
2019-07-26 2019-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 14 0.00 88 -9.28 n/a n/a n/a
2019-04-18 2019-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 14 -77.05 97 -63.40 n/a n/a n/a
2019-01-16 2018-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 61 6,000.00 265 3,685.71 n/a n/a n/a
2018-10-23 2018-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 1 -85.71 7 -86.79 n/a n/a n/a
2018-07-30 2018-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 7 -22.22 53 1,225.00 n/a n/a n/a
2018-04-26 2018-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 9 800.00 4 300.00 n/a n/a n/a
2018-01-10 2017-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 1 -88.89 1 -75.00 n/a n/a n/a
2017-10-25 2017-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-07-12 2017-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 24 -92.57 10 -89.58 n/a n/a n/a
2017-04-21 2017-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 323 15.36 96 -15.04 n/a n/a n/a
2017-01-11 2016-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 280 5,500.00 113 3,666.67 n/a n/a n/a
2016-10-07 2016-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 5 -82.14 3 -85.71 n/a n/a n/a
2016-07-18 2016-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 28 100.00 21 90.91 n/a n/a n/a
2016-04-14 2016-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 14 -48.15 11 266.67 n/a n/a n/a
2016-01-20 2015-12-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 27 107.69 3 -76.92 n/a n/a n/a
2015-10-08 2015-09-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 13 8.33 13 333.33 n/a n/a n/a
2015-07-08 2015-06-30 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 12 500.00 0 -100.00 n/a n/a n/a
2015-04-21 2015-03-31 13F ULTRAGENYX PHARMACEUTICAL IN PUT Put 2 0 n/a n/a n/a
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.