Rambus Inc.
US ˙ NasdaqGS ˙ US7509171069

SecurityRMBS / Rambus Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Simplex Trading, Llc ownership in RMBS / Rambus Inc.

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 0 shares of Rambus Inc. (US:RMBS) valued at $0 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 3,884 shares of Rambus Inc.. This represents a change in shares of -100.00% during the quarter. The current value of the position is $0 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (RMBS) in the form of stock options. The firm currently holds call options representing 8,000 of underlying shares valued at $688,240 USD and put options representing 1,900 of underlying shares valued at $163,457 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.

RMBS / Rambus 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 RAMBUS INC DEL COM 750917106 0 -3,884 -100.00 0 -100.00
2026-02-11 2025-12-31 13F RAMBUS INC DEL COM 750917106 3,884 3,884 357 0.0002
2025-02-11 2024-12-31 13F RAMBUS INC DEL COM 750917106 0 -4,450 -100.00 0 0.0000
2024-11-08 2024-09-30 13F RAMBUS INC DEL COM 750917106 4,450 4,450 0 0.0001
2024-07-25 2024-06-30 13F RAMBUS INC DEL COM 750917106 0 -2,108 -100.00 0 0.0000
2024-04-25 2024-03-31 13F RAMBUS INC DEL COM 750917106 2,108 2,108 0 0.0001
2024-02-02 2023-12-31 13F RAMBUS INC DEL COM 750917106 0 -31,157 -100.00 0 -100.00
2023-11-01 2023-09-30 13F RAMBUS INC DEL COM 750917106 31,157 15,326 96.81 2 0.00 0.0014
2023-08-04 2023-06-30 13F RAMBUS INC DEL COM 750917106 15,831 11,240 244.83 1 0.0008
2023-04-27 2023-03-31 13F RAMBUS INC DEL COM 750917106 4,591 -1,443 -23.91 0 0.0002
2023-02-02 2022-12-31 13F RAMBUS INC DEL COM 750917106 6,034 6,034 0 0.0002
2022-11-04 2022-09-30 13F RAMBUS INC DEL COM 750917106 0 -1,931 -100.00 0 -100.00
2022-08-03 2022-06-30 13F RAMBUS INC DEL COM 750917106 1,931 -2,250 -53.81 41 -69.17 0.0000
2022-05-02 2022-03-31 13F RAMBUS INC DEL COM 750917106 4,181 203 5.10 133 14.66 0.0001
2022-02-23 2021-12-31 13F/A-1 RAMBUS INC DEL COM 750917106 3,978 3,978 116 0.0001
2020-04-28 2020-03-31 13F RAMBUS INC DEL COM 750917106 0 -14,467 -100.00 0 -100.00
2020-02-05 2019-12-31 13F RAMBUS INC DEL COM 750917106 14,467 682 4.95 199 10.56 0.0004
2019-10-15 2019-09-30 13F RAMBUS INC DEL COM 750917106 13,785 6,417 87.09 180 104.55 0.0005
2019-07-26 2019-06-30 13F RAMBUS INC DEL COM 750917106 7,368 7,368 -46.55 88 -51.11 0.0002
2019-04-18 2019-03-31 13F RAMBUS INC DEL COM 750917106 0 -1,646 -100.00 0 -100.00
2019-01-16 2018-12-31 13F RAMBUS INC DEL COM 750917106 1,646 1,646 12 0.0000
2018-10-23 2018-09-30 13F RAMBUS INC DEL COM 750917106 0 -7,445 -100.00 0 -100.00
2018-07-30 2018-06-30 13F RAMBUS INC DEL COM 750917106 7,445 7,445 93 0.0004
2018-04-26 2018-03-31 13F RAMBUS INC DEL COM 750917106 0 -16,884 -100.00 0 -100.00
2018-01-10 2017-12-31 13F RAMBUS INC DEL COM 750917106 16,884 16,884 240 0.0103
2017-07-12 2017-06-30 13F RAMBUS INC DEL COM 750917106 0 -6,663 -100.00 0 -100.00
2017-04-21 2017-03-31 13F RAMBUS INC DEL COM 750917106 6,663 -5,978 -47.29 87 -50.00 0.0038
2017-01-11 2016-12-31 13F RAMBUS INC DEL COM 750917106 12,641 3,832 43.50 174 58.18 0.0104
2016-10-07 2016-09-30 13F RAMBUS INC DEL COM 750917106 8,809 1,970 28.81 110 34.15 0.0075
2016-07-18 2016-06-30 13F RAMBUS INC DEL COM 750917106 6,839 6,839 -22.36 82 -25.45 0.0055
2016-04-14 2016-03-31 13F RAMBUS INC DEL COM 750917106 0 -2,937 -100.00 0 -100.00
2016-01-20 2015-12-31 13F RAMBUS INC DEL COM 750917106 2,937 -3,051 -50.95 34 -51.43 0.0027
2015-10-08 2015-09-30 13F RAMBUS INC DEL COM 750917106 5,988 5,988 103.88 70 105.88 0.0051
2015-04-21 2015-03-31 13F RAMBUS COM 750917106 0 -3,174 -100.00 0 -100.00
2015-03-04 2014-12-31 13F RAMBUS COM 750917106 3,174 3,174 35 0.0042
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 RAMBUS INC DEL CALL Call 8,000 -75.16 688 -76.74 n/a n/a n/a
2026-02-11 2025-12-31 13F RAMBUS INC DEL CALL Call 32,200 -25.12 2,959 73,850.00 n/a n/a n/a
2025-11-12 2025-09-30 13F RAMBUS INC DEL CALL Call 43,000 82.98 4 300.00 n/a n/a n/a
2025-08-05 2025-06-30 13F RAMBUS INC DEL CALL Call 23,500 3.07 2 0.00 n/a n/a n/a
2025-05-12 2025-03-31 13F RAMBUS INC DEL CALL Call 22,800 -44.39 1 -50.00 n/a n/a n/a
2025-02-11 2024-12-31 13F RAMBUS INC DEL CALL Call 41,000 -35.84 2 0.00 n/a n/a n/a
2024-11-08 2024-09-30 13F RAMBUS INC DEL CALL Call 63,900 15.97 3 -33.33 n/a n/a n/a
2024-07-25 2024-06-30 13F RAMBUS INC DEL CALL Call 55,100 -39.18 3 -40.00 n/a n/a n/a
2024-04-25 2024-03-31 13F RAMBUS INC DEL CALL Call 90,600 0.55 6 -16.67 n/a n/a n/a
2024-02-02 2023-12-31 13F RAMBUS INC DEL CALL Call 90,100 -37.39 6 -25.00 n/a n/a n/a
2023-11-01 2023-09-30 13F RAMBUS INC DEL CALL Call 143,900 -8.87 8 -20.00 n/a n/a n/a
2023-08-04 2023-06-30 13F RAMBUS INC DEL CALL Call 157,900 51.83 10 100.00 n/a n/a n/a
2023-04-27 2023-03-31 13F RAMBUS INC DEL CALL Call 104,000 648.20 5 n/a n/a n/a
2023-02-02 2022-12-31 13F RAMBUS INC DEL CALL Call 13,900 -62.23 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F RAMBUS INC DEL CALL Call 36,800 37.31 935 62.61 n/a n/a n/a
2022-08-03 2022-06-30 13F RAMBUS INC DEL CALL Call 26,800 67.50 575 12.75 n/a n/a n/a
2022-05-02 2022-03-31 13F RAMBUS INC DEL CALL Call 16,000 -31.03 510 -25.11 n/a n/a n/a
2022-02-23 2021-12-31 13F/A RAMBUS INC DEL CALL Call 23,200 -54.24 681 -42.58 n/a n/a n/a
2022-02-04 2021-12-31 13F RAMBUS INC DEL CALL Call 50,700 1,186 n/a n/a n/a
2021-10-28 2021-09-30 13F RAMBUS INC DEL CALL Call 50,700 5.41 1,186 4.04 n/a n/a n/a
2021-08-12 2021-06-30 13F RAMBUS INC DEL CALL Call 48,100 5,519.16 1,140 -31.49 n/a n/a n/a
2021-04-26 2021-03-31 13F RAMBUS INC DEL CALL Call 856 -29.08 1,664 -21.03 n/a n/a n/a
2021-02-02 2020-12-31 13F RAMBUS INC DEL CALL Call 1,207 76.20 2,107 124.87 n/a n/a n/a
2020-10-14 2020-09-30 13F RAMBUS INC DEL CALL Call 685 -39.11 937 -45.20 n/a n/a n/a
2020-07-13 2020-06-30 13F RAMBUS INC DEL CALL Call 1,125 136.84 1,710 224.48 n/a n/a n/a
2020-04-29 2020-03-31 13F RAMBUS INC DEL CALL Call 475 45.26 527 17.11 n/a n/a n/a
2020-02-05 2019-12-31 13F RAMBUS INC DEL CALL Call 327 -24.13 450 -20.35 n/a n/a n/a
2019-10-15 2019-09-30 13F RAMBUS INC DEL CALL Call 431 -38.25 565 -32.74 n/a n/a n/a
2019-07-26 2019-06-30 13F RAMBUS INC DEL CALL Call 698 -50.43 840 -42.90 n/a n/a n/a
2019-04-18 2019-03-31 13F RAMBUS INC DEL CALL Call 1,408 23,366.67 1,471 36,675.00 n/a n/a n/a
2019-01-16 2018-12-31 13F RAMBUS INC DEL CALL Call 6 -99.23 4 -99.53 n/a n/a n/a
2018-10-23 2018-09-30 13F RAMBUS INC DEL CALL Call 780 469.34 850 397.08 n/a n/a n/a
2018-07-30 2018-06-30 13F RAMBUS INC DEL CALL Call 137 -86.78 171 338.46 n/a n/a n/a
2018-04-26 2018-03-31 13F RAMBUS INC DEL CALL Call 1,036 159.65 39 680.00 n/a n/a n/a
2018-01-10 2017-12-31 13F RAMBUS INC DEL CALL Call 399 -73.47 5 -94.19 n/a n/a n/a
2017-10-25 2017-09-30 13F RAMBUS INC DEL CALL Call 1,504 120.85 86 616.67 n/a n/a n/a
2017-07-12 2017-06-30 13F RAMBUS INC DEL CALL Call 681 43.37 12 -40.00 n/a n/a n/a
2017-04-21 2017-03-31 13F RAMBUS INC DEL CALL Call 475 97.92 20 -16.67 n/a n/a n/a
2017-01-11 2016-12-31 13F RAMBUS INC DEL CALL Call 240 -44.06 24 33.33 n/a n/a n/a
2016-10-07 2016-09-30 13F RAMBUS INC DEL CALL Call 429 19.83 18 28.57 n/a n/a n/a
2016-07-18 2016-06-30 13F RAMBUS INC DEL CALL Call 358 31.62 14 -68.89 n/a n/a n/a
2016-04-14 2016-03-31 13F RAMBUS INC DEL CALL Call 272 -2.86 45 50.00 n/a n/a n/a
2016-01-20 2015-12-31 13F RAMBUS INC DEL CALL Call 280 76.10 30 -6.25 n/a n/a n/a
2015-10-08 2015-09-30 13F RAMBUS INC DEL CALL Call 159 -5.36 32 -50.00 n/a n/a n/a
2015-07-08 2015-06-30 13F RAMBUS INC DEL CALL Call 168 1,300.00 64 2,033.33 n/a n/a n/a
2015-04-21 2015-03-31 13F RAMBUS INC DEL CALL Call 12 -92.36 3 -50.00 n/a n/a n/a
2015-03-04 2014-12-31 13F RAMBUS CALL Call 157 6 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 RAMBUS INC DEL PUT Put 1,900 -62.00 163 -64.49 n/a n/a n/a
2026-02-11 2025-12-31 13F RAMBUS INC DEL PUT Put 5,000 -80.47 459 22,850.00 n/a n/a n/a
2025-11-12 2025-09-30 13F RAMBUS INC DEL PUT Put 25,600 -75.73 3 -66.67 n/a n/a n/a
2025-08-05 2025-06-30 13F RAMBUS INC DEL PUT Put 105,500 3,667.86 7 n/a n/a n/a
2025-05-12 2025-03-31 13F RAMBUS INC DEL PUT Put 2,800 -94.26 0 -100.00 n/a n/a n/a
2025-02-11 2024-12-31 13F RAMBUS INC DEL PUT Put 48,800 -40.05 3 -33.33 n/a n/a n/a
2024-11-08 2024-09-30 13F RAMBUS INC DEL PUT Put 81,400 66.12 3 50.00 n/a n/a n/a
2024-07-25 2024-06-30 13F RAMBUS INC DEL PUT Put 49,000 -35.53 3 -50.00 n/a n/a n/a
2024-04-25 2024-03-31 13F RAMBUS INC DEL PUT Put 76,000 67.03 5 33.33 n/a n/a n/a
2024-02-02 2023-12-31 13F RAMBUS INC DEL PUT Put 45,500 -48.41 3 -25.00 n/a n/a n/a
2023-11-01 2023-09-30 13F RAMBUS INC DEL PUT Put 88,200 -24.36 5 -42.86 n/a n/a n/a
2023-08-04 2023-06-30 13F RAMBUS INC DEL PUT Put 116,600 297.95 7 600.00 n/a n/a n/a
2023-04-27 2023-03-31 13F RAMBUS INC DEL PUT Put 29,300 343.94 2 n/a n/a n/a
2023-02-02 2022-12-31 13F RAMBUS INC DEL PUT Put 6,600 -71.79 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F RAMBUS INC DEL PUT Put 23,400 -1.27 594 16.70 n/a n/a n/a
2022-08-03 2022-06-30 13F RAMBUS INC DEL PUT Put 23,700 220.27 509 116.60 n/a n/a n/a
2022-05-02 2022-03-31 13F RAMBUS INC DEL PUT Put 7,400 -69.29 235 -66.81 n/a n/a n/a
2022-02-23 2021-12-31 13F/A RAMBUS INC DEL PUT Put 24,100 88.28 708 136.79 n/a n/a n/a
2022-02-04 2021-12-31 13F RAMBUS INC DEL PUT Put 12,800 299 n/a n/a n/a
2021-10-28 2021-09-30 13F RAMBUS INC DEL PUT Put 12,800 0.00 299 -1.32 n/a n/a n/a
2021-08-12 2021-06-30 13F RAMBUS INC DEL PUT Put 12,800 13,233.33 303 62.90 n/a n/a n/a
2021-04-26 2021-03-31 13F RAMBUS INC DEL PUT Put 96 -90.82 186 -89.81 n/a n/a n/a
2021-02-02 2020-12-31 13F RAMBUS INC DEL PUT Put 1,046 1,075.28 1,826 1,409.09 n/a n/a n/a
2020-10-14 2020-09-30 13F RAMBUS INC DEL PUT Put 89 206.90 121 175.00 n/a n/a n/a
2020-07-13 2020-06-30 13F RAMBUS INC DEL PUT Put 29 -21.62 44 7.32 n/a n/a n/a
2020-04-29 2020-03-31 13F RAMBUS INC DEL PUT Put 37 -36.21 41 -48.10 n/a n/a n/a
2020-02-05 2019-12-31 13F RAMBUS INC DEL PUT Put 58 28.89 79 33.90 n/a n/a n/a
2019-10-15 2019-09-30 13F RAMBUS INC DEL PUT Put 45 104.55 59 126.92 n/a n/a n/a
2019-07-26 2019-06-30 13F RAMBUS INC DEL PUT Put 22 2,100.00 26 2,500.00 n/a n/a n/a
2019-04-18 2019-03-31 13F RAMBUS INC DEL PUT Put 1 -95.00 1 -93.33 n/a n/a n/a
2019-01-16 2018-12-31 13F RAMBUS INC DEL PUT Put 20 300.00 15 200.00 n/a n/a n/a
2018-10-23 2018-09-30 13F RAMBUS INC DEL PUT Put 5 -75.00 5 -66.67 n/a n/a n/a
2018-07-30 2018-06-30 13F RAMBUS INC DEL PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2018-04-26 2018-03-31 13F RAMBUS INC DEL PUT Put 30 -73.91 0 n/a n/a n/a
2018-01-10 2017-12-31 13F RAMBUS INC DEL PUT Put 115 0.88 0 n/a n/a n/a
2017-10-25 2017-09-30 13F RAMBUS INC DEL PUT Put 114 -0.87 0 n/a n/a n/a
2017-07-12 2017-06-30 13F RAMBUS INC DEL PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2017-04-21 2017-03-31 13F RAMBUS INC DEL PUT Put 246 -32.04 8 33.33 n/a n/a n/a
2017-01-11 2016-12-31 13F RAMBUS INC DEL PUT Put 362 -0.28 6 -88.00 n/a n/a n/a
2016-10-07 2016-09-30 13F RAMBUS INC DEL PUT Put 363 109.83 50 400.00 n/a n/a n/a
2016-07-18 2016-06-30 13F RAMBUS INC DEL PUT Put 173 367.57 10 -80.00 n/a n/a n/a
2016-04-14 2016-03-31 13F RAMBUS INC DEL PUT Put 37 -70.63 0 -100.00 n/a n/a n/a
2016-01-20 2015-12-31 13F RAMBUS INC DEL PUT Put 126 -25.00 25 -24.24 n/a n/a n/a
2015-10-08 2015-09-30 13F RAMBUS INC DEL PUT Put 168 33.33 33 32.00 n/a n/a n/a
2015-07-08 2015-06-30 13F RAMBUS INC DEL PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2015-04-21 2015-03-31 13F RAMBUS INC DEL PUT Put 3 -89.29 0 -100.00 n/a n/a n/a
2015-03-04 2014-12-31 13F RAMBUS PUT Put 28 1 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.