Omeros Corporation
US ˙ NasdaqGM ˙ US6821431029

SecurityOMER / Omeros Corporation
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership37,526 shares
Latest Disclosed Value $ 396,274
Simplex Trading, Llc ownership in OMER / Omeros Corporation

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 37,526 shares of Omeros Corporation (US:OMER) valued at $396,275 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 123,979 shares of Omeros Corporation. This represents a change in shares of -69.73% during the quarter. The current value of the position is $381,264 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (OMER) in the form of stock options. The firm currently holds call options representing 85,400 of underlying shares valued at $901,824 USD and put options representing 40,800 of underlying shares valued at $430,848 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.

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Institutional Put/Call Ratios
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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.

OMER / Omeros Corporation 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 OMEROS COM 682143102 37,526 -86,453 -69.73 396 -81.40 0.0001
2026-02-11 2025-12-31 13F OMEROS COM 682143102 123,979 101,759 457.96 2,129 0.0012
2025-11-12 2025-09-30 13F OMEROS COM 682143102 22,220 22,220 0 0.0000
2025-08-05 2025-06-30 13F OMEROS COM 682143102 0 -63,465 -100.00 0 0.0000
2025-05-12 2025-03-31 13F OMEROS COM 682143102 63,465 -41,141 -39.33 1 -100.00 0.0003
2025-02-11 2024-12-31 13F OMEROS COM 682143102 104,606 86,462 476.53 1 0.0006
2024-11-08 2024-09-30 13F OMEROS COM 682143102 18,144 -15,929 -46.75 0 0.0000
2024-07-25 2024-06-30 13F OMEROS COM 682143102 34,073 -38,404 -52.99 0 0.0001
2024-04-25 2024-03-31 13F OMEROS COM 682143102 72,477 72,477 0 0.0001
2023-08-04 2023-06-30 13F OMEROS COM 682143102 0 -1,732 -100.00 0 0.0000
2023-04-27 2023-03-31 13F OMEROS COM 682143102 1,732 -38,416 -95.69 0 0.0000
2023-02-02 2022-12-31 13F OMEROS COM 682143102 40,148 10,276 34.40 0 -100.00 0.0001
2022-11-04 2022-09-30 13F OMEROS COM 682143102 29,872 29,872 94 0.0001
2022-05-02 2022-03-31 13F OMEROS COM 682143102 0 -61,150 -100.00 0 -100.00
2022-02-23 2021-12-31 13F/A-1 OMEROS COM 682143102 61,150 -55,947 -47.78 393 -78.56 0.0004
2022-02-04 2021-12-31 13F OMEROS COM 682143102 117,097 0 1,833 0.0017
2021-10-28 2021-09-30 13F OMEROS COM 682143102 117,097 3,496 3.08 1,833 8.78 0.0017
2021-08-12 2021-06-30 13F OMEROS COM 682143102 113,601 66,209 139.71 1,685 99.88 0.0016
2021-04-26 2021-03-31 13F OMEROS COM 682143102 47,392 -22,021 -31.72 843 -14.93 0.0015
2021-02-02 2020-12-31 13F OMEROS COM 682143102 69,413 23,179 50.13 991 112.21 0.0013
2020-10-14 2020-09-30 13F OMEROS COM 682143102 46,234 32,723 242.20 467 135.86 0.0006
2020-07-13 2020-06-30 13F OMEROS COM 682143102 13,511 -5,076 -27.31 198 -20.16 0.0003
2020-04-29 2020-03-31 13F OMEROS COM 682143102 18,587 7,490 67.50 248 58.97 0.0004
2020-02-05 2019-12-31 13F OMEROS COM 682143102 11,097 11,097 -40.30 156 -37.10 0.0003
2019-10-15 2019-09-30 13F OMEROS COM 682143102 0 -766 -100.00 0 -100.00
2019-07-26 2019-06-30 13F OMEROS COM 682143102 766 766 12 0.0000
2019-04-18 2019-03-31 13F OMEROS COM 682143102 0 -16,253 -100.00 0 -100.00
2019-01-16 2018-12-31 13F OMEROS COM 682143102 16,253 -24,534 -60.15 181 -81.81 0.0005
2018-10-23 2018-09-30 13F OMEROS COM 682143102 40,787 14,464 54.95 995 108.60 0.0032
2018-07-30 2018-06-30 13F OMEROS COM 682143102 26,323 -18,062 -40.69 477 -3.64 0.0019
2018-04-26 2018-03-31 13F OMEROS COM 682143102 44,385 13,810 45.17 495 -16.67 0.0218
2018-01-10 2017-12-31 13F OMEROS COM 682143102 30,575 3,738 13.93 594 2.41 0.0256
2017-10-25 2017-09-30 13F OMEROS COM 682143102 26,837 25,079 1,426.56 580 1,605.88 0.0237
2017-07-12 2017-06-30 13F OMEROS COM 682143102 1,758 358 25.57 34 61.90 0.0015
2017-04-21 2017-03-31 13F OMEROS COM 682143102 1,400 1,400 -20.36 21 -38.24 0.0009
2017-01-11 2016-12-31 13F OMEROS COM 682143102 0 -10,580 -100.00 0 -100.00
2016-10-07 2016-09-30 13F OMEROS COM 682143102 10,580 10,146 2,337.79 118 2,850.00 0.0080
2016-07-18 2016-06-30 13F OMEROS COM 682143102 434 434 -95.90 4 -96.61 0.0003
2016-01-20 2015-12-31 13F OMEROS COM 682143102 0 -3,103 -100.00 0 -100.00
2015-10-08 2015-09-30 13F OMEROS COM 682143102 3,103 3,103 0.00 34 0.0025
2015-04-21 2015-03-31 13F OMEROS COM 682143102 0 -886 -100.00 0 -100.00
2015-03-04 2014-12-31 13F OMEROS COM 682143102 886 886 22 0.0027
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 OMEROS CALL Call 85,400 -34.05 902 -59.49 n/a n/a n/a
2026-02-11 2025-12-31 13F OMEROS CALL Call 129,500 43.09 2,224 n/a n/a n/a
2025-11-12 2025-09-30 13F OMEROS CALL Call 90,500 307.66 0 n/a n/a n/a
2025-08-05 2025-06-30 13F OMEROS CALL Call 22,200 -13.28 0 n/a n/a n/a
2025-05-12 2025-03-31 13F OMEROS CALL Call 25,600 -75.12 0 -100.00 n/a n/a n/a
2025-02-11 2024-12-31 13F OMEROS CALL Call 102,900 110.43 1 n/a n/a n/a
2024-11-08 2024-09-30 13F OMEROS CALL Call 48,900 -20.23 0 n/a n/a n/a
2024-07-25 2024-06-30 13F OMEROS CALL Call 61,300 24.34 0 n/a n/a n/a
2024-04-25 2024-03-31 13F OMEROS CALL Call 49,300 15.46 0 n/a n/a n/a
2024-02-02 2023-12-31 13F OMEROS CALL Call 42,700 29.00 0 n/a n/a n/a
2023-11-01 2023-09-30 13F OMEROS CALL Call 33,100 -82.63 0 -100.00 n/a n/a n/a
2023-08-04 2023-06-30 13F OMEROS CALL Call 190,600 531.13 1 n/a n/a n/a
2023-04-27 2023-03-31 13F OMEROS CALL Call 30,200 344.12 0 n/a n/a n/a
2023-02-02 2022-12-31 13F OMEROS CALL Call 6,800 -85.31 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F OMEROS CALL Call 46,300 8.18 145 23.93 n/a n/a n/a
2022-08-03 2022-06-30 13F OMEROS CALL Call 42,800 24.06 117 -43.48 n/a n/a n/a
2022-05-02 2022-03-31 13F OMEROS CALL Call 34,500 -60.16 207 -62.77 n/a n/a n/a
2022-02-23 2021-12-31 13F/A OMEROS CALL Call 86,600 -39.19 556 -75.06 n/a n/a n/a
2022-02-04 2021-12-31 13F OMEROS CALL Call 142,400 2,229 n/a n/a n/a
2021-10-28 2021-09-30 13F OMEROS CALL Call 142,400 0.00 2,229 5.49 n/a n/a n/a
2021-08-12 2021-06-30 13F OMEROS CALL Call 142,400 31,756.82 2,113 165.79 n/a n/a n/a
2021-04-26 2021-03-31 13F OMEROS CALL Call 447 -20.74 795 -1.24 n/a n/a n/a
2021-02-02 2020-12-31 13F OMEROS CALL Call 564 -44.32 805 -21.31 n/a n/a n/a
2020-10-14 2020-09-30 13F OMEROS CALL Call 1,013 245.73 1,023 137.35 n/a n/a n/a
2020-07-13 2020-06-30 13F OMEROS CALL Call 293 29.65 431 42.72 n/a n/a n/a
2020-04-29 2020-03-31 13F OMEROS CALL Call 226 -50.33 302 -52.89 n/a n/a n/a
2020-02-05 2019-12-31 13F OMEROS CALL Call 455 -52.85 641 -59.30 n/a n/a n/a
2019-10-15 2019-09-30 13F OMEROS CALL Call 965 123.90 1,575 132.99 n/a n/a n/a
2019-07-26 2019-06-30 13F OMEROS CALL Call 431 -66.51 676 -69.75 n/a n/a n/a
2019-04-18 2019-03-31 13F OMEROS CALL Call 1,287 198.61 2,235 365.63 n/a n/a n/a
2019-01-16 2018-12-31 13F OMEROS CALL Call 431 -20.77 480 -63.83 n/a n/a n/a
2018-10-23 2018-09-30 13F OMEROS CALL Call 544 177.55 1,327 273.80 n/a n/a n/a
2018-07-30 2018-06-30 13F OMEROS CALL Call 196 -70.57 355 810.26 n/a n/a n/a
2018-04-26 2018-03-31 13F OMEROS CALL Call 666 243.30 39 -11.36 n/a n/a n/a
2018-01-10 2017-12-31 13F OMEROS CALL Call 194 -0.51 44 37.50 n/a n/a n/a
2017-10-25 2017-09-30 13F OMEROS CALL Call 195 -21.05 32 -68.63 n/a n/a n/a
2017-07-12 2017-06-30 13F OMEROS CALL Call 247 11.76 102 39.73 n/a n/a n/a
2017-04-21 2017-03-31 13F OMEROS CALL Call 221 -76.06 73 265.00 n/a n/a n/a
2017-01-11 2016-12-31 13F OMEROS CALL Call 923 4,095.45 20 1,900.00 n/a n/a n/a
2016-10-07 2016-09-30 13F OMEROS CALL Call 22 10.00 1 -75.00 n/a n/a n/a
2016-07-18 2016-06-30 13F OMEROS CALL Call 20 -89.36 4 -91.67 n/a n/a n/a
2016-04-14 2016-03-31 13F OMEROS CALL Call 188 -46.89 48 -46.07 n/a n/a n/a
2016-01-20 2015-12-31 13F OMEROS CALL Call 354 -29.06 89 32.84 n/a n/a n/a
2015-10-08 2015-09-30 13F OMEROS CALL Call 499 62.01 67 252.63 n/a n/a n/a
2015-07-08 2015-06-30 13F OMEROS CALL Call 308 3.70 19 -64.81 n/a n/a n/a
2015-04-21 2015-03-31 13F OMEROS CALL Call 297 1,880.00 54 500.00 n/a n/a n/a
2015-03-04 2014-12-31 13F OMEROS CALL Call 15 9 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 OMEROS PUT Put 40,800 -65.91 431 -79.08 n/a n/a n/a
2026-02-11 2025-12-31 13F OMEROS PUT Put 119,700 35.25 2,056 n/a n/a n/a
2025-11-12 2025-09-30 13F OMEROS PUT Put 88,500 2,581.82 0 n/a n/a n/a
2025-08-05 2025-06-30 13F OMEROS PUT Put 3,300 -83.33 0 n/a n/a n/a
2025-05-12 2025-03-31 13F OMEROS PUT Put 19,800 -68.32 0 n/a n/a n/a
2025-02-11 2024-12-31 13F OMEROS PUT Put 62,500 17.92 1 n/a n/a n/a
2024-11-08 2024-09-30 13F OMEROS PUT Put 53,000 -24.82 0 n/a n/a n/a
2024-07-25 2024-06-30 13F OMEROS PUT Put 70,500 67.86 0 n/a n/a n/a
2024-04-25 2024-03-31 13F OMEROS PUT Put 42,000 292.52 0 n/a n/a n/a
2024-02-02 2023-12-31 13F OMEROS PUT Put 10,700 -88.31 0 n/a n/a n/a
2023-11-01 2023-09-30 13F OMEROS PUT Put 91,500 553.57 0 n/a n/a n/a
2023-08-04 2023-06-30 13F OMEROS PUT Put 14,000 -18.60 0 n/a n/a n/a
2023-04-27 2023-03-31 13F OMEROS PUT Put 17,200 24.64 0 n/a n/a n/a
2023-02-02 2022-12-31 13F OMEROS PUT Put 13,800 -82.22 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F OMEROS PUT Put 77,600 273.08 244 328.07 n/a n/a n/a
2022-08-03 2022-06-30 13F OMEROS PUT Put 20,800 342.55 57 103.57 n/a n/a n/a
2022-05-02 2022-03-31 13F OMEROS PUT Put 4,700 -93.13 28 -93.62 n/a n/a n/a
2022-02-23 2021-12-31 13F/A OMEROS PUT Put 68,400 -54.82 439 -81.48 n/a n/a n/a
2022-02-04 2021-12-31 13F OMEROS PUT Put 151,400 2,370 n/a n/a n/a
2021-10-28 2021-09-30 13F OMEROS PUT Put 151,400 0.00 2,370 5.52 n/a n/a n/a
2021-08-12 2021-06-30 13F OMEROS PUT Put 151,400 108,042.86 2,246 802.01 n/a n/a n/a
2021-04-26 2021-03-31 13F OMEROS PUT Put 140 -60.00 249 -50.10 n/a n/a n/a
2021-02-02 2020-12-31 13F OMEROS PUT Put 350 8.36 499 53.07 n/a n/a n/a
2020-10-14 2020-09-30 13F OMEROS PUT Put 323 67.36 326 14.79 n/a n/a n/a
2020-07-13 2020-06-30 13F OMEROS PUT Put 193 -62.08 284 -58.24 n/a n/a n/a
2020-04-29 2020-03-31 13F OMEROS PUT Put 509 14.90 680 8.97 n/a n/a n/a
2020-02-05 2019-12-31 13F OMEROS PUT Put 443 140.76 624 108.00 n/a n/a n/a
2019-10-15 2019-09-30 13F OMEROS PUT Put 184 52.07 300 58.73 n/a n/a n/a
2019-07-26 2019-06-30 13F OMEROS PUT Put 121 -32.02 189 -38.83 n/a n/a n/a
2019-04-18 2019-03-31 13F OMEROS PUT Put 178 -9.18 309 41.74 n/a n/a n/a
2019-01-16 2018-12-31 13F OMEROS PUT Put 196 345.45 218 103.74 n/a n/a n/a
2018-10-23 2018-09-30 13F OMEROS PUT Put 44 -46.34 107 -27.70 n/a n/a n/a
2018-07-30 2018-06-30 13F OMEROS PUT Put 82 -77.72 148 59.14 n/a n/a n/a
2018-04-26 2018-03-31 13F OMEROS PUT Put 368 32.37 93 244.44 n/a n/a n/a
2018-01-10 2017-12-31 13F OMEROS PUT Put 278 3.35 27 -35.71 n/a n/a n/a
2017-10-25 2017-09-30 13F OMEROS PUT Put 269 20.63 42 0.00 n/a n/a n/a
2017-07-12 2017-06-30 13F OMEROS PUT Put 223 -56.78 42 110.00 n/a n/a n/a
2017-04-21 2017-03-31 13F OMEROS PUT Put 516 154.19 20 -68.75 n/a n/a n/a
2017-01-11 2016-12-31 13F OMEROS PUT Put 203 128.09 64 64.10 n/a n/a n/a
2016-10-07 2016-09-30 13F OMEROS PUT Put 89 641.67 39 333.33 n/a n/a n/a
2016-07-18 2016-06-30 13F OMEROS PUT Put 12 -72.09 9 50.00 n/a n/a n/a
2016-04-14 2016-03-31 13F OMEROS PUT Put 43 -69.93 6 -25.00 n/a n/a n/a
2016-01-20 2015-12-31 13F OMEROS PUT Put 143 1,000.00 8 33.33 n/a n/a n/a
2015-10-08 2015-09-30 13F OMEROS PUT Put 13 333.33 6 500.00 n/a n/a n/a
2015-07-08 2015-06-30 13F OMEROS PUT Put 3 -85.00 1 -50.00 n/a n/a n/a
2015-04-21 2015-03-31 13F OMEROS PUT Put 20 -13.04 2 -33.33 n/a n/a n/a
2015-03-04 2014-12-31 13F OMEROS PUT Put 23 3 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.