奧梅羅斯公司
US ˙ NasdaqGM ˙ US6821431029

SecurityOMER / Omeros Corporation
InstitutionCitigroup Inc
Latest Disclosed Ownership30,790 shares
Latest Disclosed Value $ 325,143
Citigroup Inc ownership in OMER / Omeros Corporation

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 30,790 shares of Omeros Corporation (US:OMER) valued at $325,142 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 27,489 shares of Omeros Corporation. This represents a change in shares of 12.01% during the quarter. The current value of the position is $315,598 USD.

Citigroup Inc 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 0 of underlying shares valued at $0 USD and put options representing 0 of underlying shares valued at $0 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)
2026-05-11 2026-03-31 13F OMEROS COM 682143102 30,790 3,301 12.01 325 -31.14 0.0001
2026-02-13 2025-12-31 13F OMEROS COM 682143102 27,489 21,972 398.26 472 2,045.45 0.0002
2025-11-10 2025-09-30 13F OMEROS COM 682143102 5,517 -17,172 -75.68 23 -67.65 0.0000
2025-08-11 2025-06-30 13F OMEROS COM 682143102 22,689 -27,425 -54.73 68 -83.45 0.0000
2025-05-12 2025-03-31 13F OMEROS COM 682143102 50,114 5,939 13.44 412 -5.73 0.0002
2025-02-12 2024-12-31 13F OMEROS COM 682143102 44,175 3,128 7.62 436 169.14 0.0003
2024-11-12 2024-09-30 13F OMEROS COM 682143102 41,047 28,176 218.91 163 211.54 0.0001
2024-08-12 2024-06-30 13F OMEROS COM 682143102 12,871 1,676 14.97 52 36.84 0.0000
2024-05-10 2024-03-31 13F OMEROS COM 682143102 11,195 2,424 27.64 39 35.71 0.0000
2024-02-09 2023-12-31 13F OMEROS COM 682143102 8,771 7,870 873.47 29 1,300.00 0.0000
2023-12-06 2023-09-30 13F/A-1 OMEROS COM 682143102 901 -18,296 -95.31 3 -98.08 0.0000
2023-11-09 2023-09-30 13F OMEROS COM 682143102 901 -18,296 3 0.0000
2023-08-10 2023-06-30 13F OMEROS COM 682143102 19,197 -48,835 -71.78 104 -67.09 0.0001
2023-05-11 2023-03-31 13F OMEROS COM 682143102 68,032 67,277 8,910.86 316 31,500.00 0.0002
2023-02-09 2022-12-31 13F OMEROS COM 682143102 755 -3,004 -79.91 2 -90.91 0.0000
2022-11-10 2022-09-30 13F OMEROS COM 682143102 3,759 1,672 80.11 11 83.33 0.0000
2022-08-10 2022-06-30 13F OMEROS COM 682143102 2,087 -11,050 -84.11 6 -92.41 0.0000
2022-05-12 2022-03-31 13F OMEROS COM 682143102 13,137 -8,575 -39.49 79 -43.57 0.0000
2022-02-10 2021-12-31 13F OMEROS COM 682143102 21,712 -4,490 -17.14 140 -61.22 0.0001
2021-11-10 2021-09-30 13F OMEROS COM 682143102 26,202 13,247 102.25 361 88.02 0.0002
2021-08-10 2021-06-30 13F OMEROS COM 682143102 12,955 3,574 38.10 192 14.97 0.0001
2021-05-13 2021-03-31 13F OMEROS COM 682143102 9,381 -8,112 -46.37 167 -33.20 0.0001
2021-02-11 2020-12-31 13F OMEROS COM 682143102 17,493 4,656 36.27 250 93.80 0.0001
2020-11-12 2020-09-30 13F OMEROS COM 682143102 12,837 -12,750 -49.83 129 -65.78 0.0001
2020-08-12 2020-06-30 13F OMEROS COM 682143102 25,587 -16,407 -39.07 377 -32.92 0.0003
2020-05-12 2020-03-31 13F OMEROS COM 682143102 41,994 11,102 35.94 562 28.90 0.0005
2020-02-12 2019-12-31 13F OMEROS COM 682143102 30,892 2,952 10.57 436 -4.39 0.0003
2019-11-08 2019-09-30 13F OMEROS COM 682143102 27,940 24,897 818.17 456 870.21 0.0004
2019-08-12 2019-06-30 13F OMEROS COM 682143102 3,043 -6,869 -69.30 47 -72.67 0.0000
2019-05-13 2019-03-31 13F OMEROS COM 682143102 9,912 -38,304 -79.44 172 -67.97 0.0002
2019-02-12 2018-12-31 13F OMEROS COM 682143102 48,216 29,129 152.61 537 15.48 0.0005
2018-11-13 2018-09-30 13F OMEROS COM 682143102 19,087 10,786 129.94 465 207.95 0.0004
2018-08-10 2018-06-30 13F OMEROS COM 682143102 8,301 -14,069 -62.89 151 -39.60 0.0001
2018-05-11 2018-03-31 13F OMEROS COM 682143102 22,370 -1,047 -4.47 250 -45.05 0.0002
2018-02-12 2017-12-31 13F OMEROS COM 682143102 23,417 -17,159 -42.29 455 -48.12 0.0004
2017-11-13 2017-09-30 13F OMEROS COM 682143102 40,576 18,945 87.58 877 103.48 0.0007
2017-08-11 2017-06-30 13F OMEROS COM 682143102 21,631 20,014 1,237.72 431 1,695.83 0.0004
2017-05-12 2017-03-31 13F OMEROS COM 682143102 1,617 -1,396 -46.33 24 -20.00 0.0000
2017-02-10 2016-12-31 13F OMEROS COM 682143102 3,013 2,414 403.01 30 328.57 0.0000
2016-11-10 2016-09-30 13F OMEROS COM 682143102 599 -3,518 -85.45 7 -83.72 0.0000
2016-08-12 2016-06-30 13F OMEROS COM 682143102 4,117 -23,339 -85.01 43 -89.79 0.0000
2016-05-13 2016-03-31 13F OMEROS COM 682143102 27,456 11,600 73.16 421 69.08 0.0005
2016-02-12 2015-12-31 13F OMEROS COM 682143102 15,856 14,650 1,214.76 249 1,815.38 0.0002
2015-11-13 2015-09-30 13F OMEROS COM 682143102 1,206 -9,333 -88.56 13 -93.12 0.0000
2015-08-13 2015-06-30 13F OMEROS COM 682143102 10,539 -2,444 -18.82 189 -33.92 0.0002
2015-05-14 2015-03-31 13F OMEROS COM 682143102 12,983 -7,663 -37.12 286 -44.03 0.0003
2015-02-17 2014-12-31 13F OMEROS COM 682143102 20,646 11,017 114.41 511 315.45 0.0005
2014-11-14 2014-09-30 13F OMEROS COM 682143102 9,629 3,562 58.71 123 16.04 0.0001
2014-08-14 2014-06-30 13F OMEROS COM 682143102 6,067 -1,428 -19.05 106 17.78 0.0001
2014-05-15 2014-03-31 13F OMEROS COM 682143102 7,495 -8,944 -54.41 90 -51.35 0.0001
2014-02-14 2013-12-31 13F OMEROS COM 682143102 16,439 10,682 185.55 185 230.36 0.0002
2013-11-14 2013-09-30 13F OMEROS COM 682143102 5,757 5,671 6,594.19 56 0.0001
2013-08-14 2013-06-30 13F OMEROS COM 682143102 86 86 0 0.0000
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
(%)
2022-05-12 2022-03-31 13F OMEROS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-10 2021-12-31 13F OMEROS COM Call 35,000 0.00 225 -53.42 n/a n/a n/a
2021-11-10 2021-09-30 13F OMEROS COM Call 35,000 0.00 483 -6.94 n/a n/a n/a
2021-08-10 2021-06-30 13F OMEROS COM Call 35,000 0.00 519 -16.69 n/a n/a n/a
2021-05-13 2021-03-31 13F OMEROS COM Call 35,000 623 n/a n/a n/a
2020-08-12 2020-06-30 13F OMEROS COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-05-12 2020-03-31 13F OMEROS COM Call 5,300 -73.10 71 -74.46 n/a n/a n/a
2020-02-12 2019-12-31 13F OMEROS COM Call 19,700 -31.60 278 -40.85 n/a n/a n/a
2019-11-08 2019-09-30 13F OMEROS COM Call 28,800 -7.10 470 -3.29 n/a n/a n/a
2019-08-12 2019-06-30 13F OMEROS COM Call 31,000 -22.69 486 -30.27 n/a n/a n/a
2019-05-13 2019-03-31 13F OMEROS COM Call 40,100 143.03 697 278.80 n/a n/a n/a
2019-02-12 2018-12-31 13F OMEROS COM Call 16,500 -43.49 184 -74.19 n/a n/a n/a
2018-11-13 2018-09-30 13F OMEROS COM Call 29,200 -21.72 713 5.32 n/a n/a n/a
2018-08-10 2018-06-30 13F OMEROS COM Call 37,300 60.78 677 161.39 n/a n/a n/a
2018-05-11 2018-03-31 13F OMEROS COM Call 23,200 -23.18 259 -55.88 n/a n/a n/a
2018-02-12 2017-12-31 13F OMEROS COM Call 30,200 51.76 587 36.51 n/a n/a n/a
2017-11-13 2017-09-30 13F OMEROS COM Call 19,900 342.22 430 377.78 n/a n/a n/a
2017-08-11 2017-06-30 13F OMEROS COM Call 4,500 -83.81 90 -78.57 n/a n/a n/a
2017-05-12 2017-03-31 13F OMEROS COM Call 27,800 195.74 420 351.61 n/a n/a n/a
2017-02-10 2016-12-31 13F OMEROS COM Call 9,400 93 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
(%)
2020-08-12 2020-06-30 13F OMEROS COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-05-12 2020-03-31 13F OMEROS COM Put 31,500 -6.80 421 -11.55 n/a n/a n/a
2020-02-12 2019-12-31 13F OMEROS COM Put 33,800 79.79 476 55.05 n/a n/a n/a
2019-11-08 2019-09-30 13F OMEROS COM Put 18,800 46.88 307 52.74 n/a n/a n/a
2019-08-12 2019-06-30 13F OMEROS COM Put 12,800 -42.60 201 -48.06 n/a n/a n/a
2019-05-13 2019-03-31 13F OMEROS COM Put 22,300 -8.61 387 42.28 n/a n/a n/a
2019-02-12 2018-12-31 13F OMEROS COM Put 24,400 33.33 272 -39.15 n/a n/a n/a
2018-11-13 2018-09-30 13F OMEROS COM Put 18,300 56.41 447 110.85 n/a n/a n/a
2018-08-10 2018-06-30 13F OMEROS COM Put 11,700 3.54 212 68.25 n/a n/a n/a
2018-05-11 2018-03-31 13F OMEROS COM Put 11,300 73.85 126 0.00 n/a n/a n/a
2018-02-12 2017-12-31 13F OMEROS COM Put 6,500 -59.12 126 -63.37 n/a n/a n/a
2017-11-13 2017-09-30 13F OMEROS COM Put 15,900 245.65 344 273.91 n/a n/a n/a
2017-08-11 2017-06-30 13F OMEROS COM Put 4,600 43.75 92 91.67 n/a n/a n/a
2017-05-12 2017-03-31 13F OMEROS COM Put 3,200 60.00 48 140.00 n/a n/a n/a
2017-02-10 2016-12-31 13F OMEROS COM Put 2,000 20 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.