Repligen Corporation
US ˙ NasdaqGS ˙ US7599161095

SecurityRGEN / Repligen Corporation
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership903 shares
Latest Disclosed Value $ 106,391
Simplex Trading, Llc ownership in RGEN / Repligen Corporation

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 903 shares of Repligen Corporation (US:RGEN) valued at $106,391 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 0 shares of Repligen Corporation. The current value of the position is $109,922 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (RGEN) in the form of stock options. The firm currently holds call options representing 900 of underlying shares valued at $106,037 USD and put options representing 2,200 of underlying shares valued at $259,204 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.

RGEN / Repligen 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 REPLIGEN COM 759916109 903 903 106 0.0001
2026-02-11 2025-12-31 13F REPLIGEN COM 759916109 0 -2,943 -100.00 0 0.0000
2025-11-12 2025-09-30 13F REPLIGEN COM 759916109 2,943 2,943 0 0.0002
2025-08-05 2025-06-30 13F REPLIGEN COM 759916109 0 -3,504 -100.00 0 0.0000
2025-05-12 2025-03-31 13F REPLIGEN COM 759916109 3,504 223 6.80 0 0.0003
2025-02-11 2024-12-31 13F REPLIGEN COM 759916109 3,281 -876 -21.07 0 0.0003
2024-11-08 2024-09-30 13F REPLIGEN COM 759916109 4,157 -2,864 -40.79 1 0.0004
2024-07-25 2024-06-30 13F REPLIGEN COM 759916109 7,021 7,021 1 0.0005
2024-02-02 2023-12-31 13F REPLIGEN COM 759916109 0 -2,433 -100.00 0 0.0000
2023-11-01 2023-09-30 13F REPLIGEN COM 759916109 2,433 -293 -10.75 0 0.0003
2023-08-04 2023-06-30 13F REPLIGEN COM 759916109 2,726 2,726 0 0.0003
2021-04-26 2021-03-31 13F REPLIGEN COM 759916109 0 -2,707 -100.00 0 -100.00
2021-02-02 2020-12-31 13F REPLIGEN COM 759916109 2,707 2,080 331.74 518 463.04 0.0007
2020-10-14 2020-09-30 13F REPLIGEN COM 759916109 627 -2,215 -77.94 92 -73.79 0.0001
2020-07-13 2020-06-30 13F REPLIGEN COM 759916109 2,842 2,842 353.27 351 281.52 0.0006
2019-07-26 2019-06-30 13F REPLIGEN COM 759916109 0 -14 -100.00 0 -100.00 0.0000
2019-04-18 2019-03-31 13F REPLIGEN COM 759916109 14 -4,666 -99.70 0 -100.00
2019-01-16 2018-12-31 13F REPLIGEN COM 759916109 4,680 4,680 33,328.57 246 0.0007
2018-04-26 2018-03-31 13F REPLIGEN COM 759916109 0 -2,463 -100.00 0 -100.00
2018-01-10 2017-12-31 13F REPLIGEN COM 759916109 2,463 -1,222 -33.16 89 -36.88 0.0038
2017-10-25 2017-09-30 13F REPLIGEN COM 759916109 3,685 3,685 49.61 141 58.43 0.0058
2017-07-12 2017-06-30 13F REPLIGEN COM 759916109 0 -3,777 -100.00 0 -100.00
2017-04-21 2017-03-31 13F REPLIGEN COM 759916109 3,777 3,777 132 0.0057
2016-10-07 2016-09-30 13F REPLIGEN COM 759916109 0 -5,330 -100.00 0 -100.00
2016-07-18 2016-06-30 13F REPLIGEN COM 759916109 5,330 5,330 0.00 145 0.0097
2016-01-20 2015-12-31 13F REPLIGEN COM 759916109 0 -777 -100.00 0 -100.00
2015-10-08 2015-09-30 13F REPLIGEN COM 759916109 777 777 21 0.0015
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 REPLIGEN CALL Call 900 0.00 106 -27.89 n/a n/a n/a
2026-02-11 2025-12-31 13F REPLIGEN CALL Call 900 -43.75 147 n/a n/a n/a
2025-11-12 2025-09-30 13F REPLIGEN CALL Call 1,600 33.33 0 n/a n/a n/a
2025-08-05 2025-06-30 13F REPLIGEN CALL Call 1,200 -70.73 0 n/a n/a n/a
2025-05-12 2025-03-31 13F REPLIGEN CALL Call 4,100 -57.29 1 -100.00 n/a n/a n/a
2025-02-11 2024-12-31 13F REPLIGEN CALL Call 9,600 7.87 1 0.00 n/a n/a n/a
2024-11-08 2024-09-30 13F REPLIGEN CALL Call 8,900 -47.34 1 -50.00 n/a n/a n/a
2024-07-25 2024-06-30 13F REPLIGEN CALL Call 16,900 -39.43 2 -60.00 n/a n/a n/a
2024-04-25 2024-03-31 13F REPLIGEN CALL Call 27,900 -58.36 5 -58.33 n/a n/a n/a
2024-02-02 2023-12-31 13F REPLIGEN CALL Call 67,000 3,841.18 12 n/a n/a n/a
2023-11-01 2023-09-30 13F REPLIGEN CALL Call 1,700 -70.18 0 n/a n/a n/a
2023-08-04 2023-06-30 13F REPLIGEN CALL Call 5,700 -50.43 1 -100.00 n/a n/a n/a
2023-04-27 2023-03-31 13F REPLIGEN CALL Call 11,500 -68.92 2 -83.33 n/a n/a n/a
2023-02-02 2022-12-31 13F REPLIGEN CALL Call 37,000 598.11 6 -99.39 n/a n/a n/a
2022-11-04 2022-09-30 13F REPLIGEN CALL Call 5,300 103.85 991 134.83 n/a n/a n/a
2022-08-03 2022-06-30 13F REPLIGEN CALL Call 2,600 -72.63 422 -76.37 n/a n/a n/a
2022-05-02 2022-03-31 13F REPLIGEN CALL Call 9,500 137.50 1,786 68.65 n/a n/a n/a
2022-02-23 2021-12-31 13F/A REPLIGEN CALL Call 4,000 90.48 1,059 152.74 n/a n/a n/a
2022-02-04 2021-12-31 13F REPLIGEN CALL Call 2,100 419 n/a n/a n/a
2021-10-28 2021-09-30 13F REPLIGEN CALL Call 2,100 0.00 419 0.00 n/a n/a n/a
2021-08-12 2021-06-30 13F REPLIGEN CALL Call 2,100 6,900.00 419 n/a n/a n/a
2021-04-26 2021-03-31 13F REPLIGEN CALL Call 30 -16.67 0 -100.00 n/a n/a n/a
2021-02-02 2020-12-31 13F REPLIGEN CALL Call 36 -47.06 689 -31.31 n/a n/a n/a
2020-10-14 2020-09-30 13F REPLIGEN CALL Call 68 257.89 1,003 328.63 n/a n/a n/a
2020-07-13 2020-06-30 13F REPLIGEN CALL Call 19 -89.20 234 -86.23 n/a n/a n/a
2020-04-29 2020-03-31 13F REPLIGEN CALL Call 176 -32.82 1,699 -29.88 n/a n/a n/a
2020-02-05 2019-12-31 13F REPLIGEN CALL Call 262 -27.42 2,423 -12.46 n/a n/a n/a
2019-10-15 2019-09-30 13F REPLIGEN CALL Call 361 -19.42 2,768 -28.10 n/a n/a n/a
2019-07-26 2019-06-30 13F REPLIGEN CALL Call 448 87.45 3,850 172.66 n/a n/a n/a
2019-04-18 2019-03-31 13F REPLIGEN CALL Call 239 198.75 1,412 235.39 n/a n/a n/a
2019-01-16 2018-12-31 13F REPLIGEN CALL Call 80 -75.38 421 -76.64 n/a n/a n/a
2018-10-23 2018-09-30 13F REPLIGEN CALL Call 325 5.86 1,802 24.79 n/a n/a n/a
2018-07-30 2018-06-30 13F REPLIGEN CALL Call 307 320.55 1,444 20,528.57 n/a n/a n/a
2018-04-26 2018-03-31 13F REPLIGEN CALL Call 73 -76.53 7 -30.00 n/a n/a n/a
2018-01-10 2017-12-31 13F REPLIGEN CALL Call 311 23.41 10 25.00 n/a n/a n/a
2017-10-25 2017-09-30 13F REPLIGEN CALL Call 252 -1.95 8 -72.41 n/a n/a n/a
2017-07-12 2017-06-30 13F REPLIGEN CALL Call 257 655.88 29 480.00 n/a n/a n/a
2017-04-21 2017-03-31 13F REPLIGEN CALL Call 34 -66.99 5 -76.19 n/a n/a n/a
2017-01-11 2016-12-31 13F REPLIGEN CALL Call 103 -32.68 21 -36.36 n/a n/a n/a
2016-10-07 2016-09-30 13F REPLIGEN CALL Call 153 -35.71 33 0.00 n/a n/a n/a
2016-07-18 2016-06-30 13F REPLIGEN CALL Call 238 81.68 33 153.85 n/a n/a n/a
2016-04-14 2016-03-31 13F REPLIGEN CALL Call 131 285.29 13 160.00 n/a n/a n/a
2016-01-20 2015-12-31 13F REPLIGEN CALL Call 34 209.09 5 -61.54 n/a n/a n/a
2015-10-08 2015-09-30 13F REPLIGEN CALL Call 11 -45.00 0 -100.00 n/a n/a n/a
2015-07-08 2015-06-30 13F REPLIGEN CALL Call 20 81.82 18 350.00 n/a n/a n/a
2015-04-21 2015-03-31 13F REPLIGEN CALL Call 11 -26.67 4 100.00 n/a n/a n/a
2015-03-04 2014-12-31 13F REPLIGEN CALL Call 15 2 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 REPLIGEN PUT Put 2,200 69.23 259 21.60 n/a n/a n/a
2026-02-11 2025-12-31 13F REPLIGEN PUT Put 1,300 8.33 213 n/a n/a n/a
2025-11-12 2025-09-30 13F REPLIGEN PUT Put 1,200 200.00 0 n/a n/a n/a
2025-08-05 2025-06-30 13F REPLIGEN PUT Put 400 -92.86 0 n/a n/a n/a
2025-05-12 2025-03-31 13F REPLIGEN PUT Put 5,600 -79.03 1 -100.00 n/a n/a n/a
2025-02-11 2024-12-31 13F REPLIGEN PUT Put 26,700 169.70 4 200.00 n/a n/a n/a
2024-11-08 2024-09-30 13F REPLIGEN PUT Put 9,900 -13.16 1 0.00 n/a n/a n/a
2024-07-25 2024-06-30 13F REPLIGEN PUT Put 11,400 470.00 1 n/a n/a n/a
2024-04-25 2024-03-31 13F REPLIGEN PUT Put 2,000 -83.47 0 -100.00 n/a n/a n/a
2024-02-02 2023-12-31 13F REPLIGEN PUT Put 12,100 175.00 2 n/a n/a n/a
2023-11-01 2023-09-30 13F REPLIGEN PUT Put 4,400 -42.86 1 -100.00 n/a n/a n/a
2023-08-04 2023-06-30 13F REPLIGEN PUT Put 7,700 1,440.00 1 n/a n/a n/a
2023-04-27 2023-03-31 13F REPLIGEN PUT Put 500 -66.67 0 n/a n/a n/a
2023-02-02 2022-12-31 13F REPLIGEN PUT Put 1,500 -75.81 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F REPLIGEN PUT Put 6,200 463.64 1,160 551.69 n/a n/a n/a
2022-08-03 2022-06-30 13F REPLIGEN PUT Put 1,100 -21.43 178 -32.32 n/a n/a n/a
2022-05-02 2022-03-31 13F REPLIGEN PUT Put 1,400 0.00 263 -28.92 n/a n/a n/a
2022-02-23 2021-12-31 13F/A REPLIGEN PUT Put 1,400 55.56 370 106.70 n/a n/a n/a
2022-02-04 2021-12-31 13F REPLIGEN PUT Put 900 179 n/a n/a n/a
2021-10-28 2021-09-30 13F REPLIGEN PUT Put 900 0.00 179 0.00 n/a n/a n/a
2021-08-12 2021-06-30 13F REPLIGEN PUT Put 900 1,566.67 179 n/a n/a n/a
2021-04-26 2021-03-31 13F REPLIGEN PUT Put 54 -60.87 0 -100.00 n/a n/a n/a
2021-02-02 2020-12-31 13F REPLIGEN PUT Put 138 -17.37 2,644 7.35 n/a n/a n/a
2020-10-14 2020-09-30 13F REPLIGEN PUT Put 167 -23.39 2,463 -8.57 n/a n/a n/a
2020-07-13 2020-06-30 13F REPLIGEN PUT Put 218 30.54 2,694 67.12 n/a n/a n/a
2020-04-29 2020-03-31 13F REPLIGEN PUT Put 167 -67.00 1,612 -65.56 n/a n/a n/a
2020-02-05 2019-12-31 13F REPLIGEN PUT Put 506 26.50 4,680 52.59 n/a n/a n/a
2019-10-15 2019-09-30 13F REPLIGEN PUT Put 400 33.78 3,067 19.38 n/a n/a n/a
2019-07-26 2019-06-30 13F REPLIGEN PUT Put 299 118.25 2,569 217.55 n/a n/a n/a
2019-04-18 2019-03-31 13F REPLIGEN PUT Put 137 15.13 809 29.03 n/a n/a n/a
2019-01-16 2018-12-31 13F REPLIGEN PUT Put 119 197.50 627 183.71 n/a n/a n/a
2018-10-23 2018-09-30 13F REPLIGEN PUT Put 40 -66.39 221 -64.75 n/a n/a n/a
2018-04-26 2018-03-31 13F REPLIGEN PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-01-10 2017-12-31 13F REPLIGEN PUT Put 57 -24.00 21 -12.50 n/a n/a n/a
2017-10-25 2017-09-30 13F REPLIGEN PUT Put 75 27.12 24 26.32 n/a n/a n/a
2017-07-12 2017-06-30 13F REPLIGEN PUT Put 59 -55.64 19 -45.71 n/a n/a n/a
2017-04-21 2017-03-31 13F REPLIGEN PUT Put 133 77.33 35 1,066.67 n/a n/a n/a
2017-01-11 2016-12-31 13F REPLIGEN PUT Put 75 0.00 3 0.00 n/a n/a n/a
2016-10-07 2016-09-30 13F REPLIGEN PUT Put 75 -38.52 3 -85.00 n/a n/a n/a
2016-07-18 2016-06-30 13F REPLIGEN PUT Put 122 125.93 20 122.22 n/a n/a n/a
2016-04-14 2016-03-31 13F REPLIGEN PUT Put 54 125.00 9 80.00 n/a n/a n/a
2016-01-20 2015-12-31 13F REPLIGEN PUT Put 24 242.86 5 150.00 n/a n/a n/a
2015-10-08 2015-09-30 13F REPLIGEN PUT Put 7 -70.83 2 -60.00 n/a n/a n/a
2015-07-08 2015-06-30 13F REPLIGEN PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2015-04-21 2015-03-31 13F REPLIGEN PUT Put 1 0.00 0 n/a n/a n/a
2015-03-04 2014-12-31 13F REPLIGEN PUT Put 1 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.