Rambus Inc.
US ˙ NasdaqGS ˙ US7509171069

SecurityRMBS / Rambus Inc.
InstitutionJane Street Group, Llc
Latest Disclosed Ownership5,426 shares
Latest Disclosed Value $ 466,798
Jane Street Group, Llc ownership in RMBS / Rambus Inc.

On May 12, 2026 - Jane Street Group, Llc filed a 13F-HR form disclosing ownership of 5,426 shares of Rambus Inc. (US:RMBS) valued at $466,799 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 5,455 shares of Rambus Inc.. This represents a change in shares of -0.53% during the quarter. The current value of the position is $788,452 USD.

Jane Street Group, 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 110,000 of underlying shares valued at $9,463,300 USD and put options representing 53,100 of underlying shares valued at $4,568,193 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)
2026-05-12 2026-03-31 13F RAMBUS INC DEL COM 750917106 5,426 -29 -0.53 467 -6.99 0.0000
2026-02-12 2025-12-31 13F RAMBUS INC DEL COM 750917106 5,455 -187,695 -97.18 501 -97.51 0.0001
2025-11-14 2025-09-30 13F RAMBUS INC DEL COM 750917106 193,150 84,229 77.33 20,126 188.63 0.0031
2025-08-14 2025-06-30 13F RAMBUS INC DEL COM 750917106 108,921 -239,370 -68.73 6,973 -61.33 0.0014
2025-05-19 2025-03-31 13F/A-1 RAMBUS INC DEL COM 750917106 348,291 123,670 55.06 18,033 51.87 0.0045
2025-05-14 2025-03-31 13F RAMBUS INC DEL COM 750917106 348,291 123,670 18,033 0.0038
2025-02-14 2024-12-31 13F RAMBUS INC DEL COM 750917106 224,621 -204,986 -47.71 11,873 -34.54 0.0026
2024-11-15 2024-09-30 13F RAMBUS INC DEL COM 750917106 429,607 293,596 215.86 18,138 126.95 0.0040
2024-08-15 2024-06-30 13F RAMBUS INC DEL COM 750917106 136,011 70,079 106.29 7,992 96.12 0.0018
2024-05-16 2024-03-31 13F RAMBUS INC DEL COM 750917106 65,932 -215,079 -76.54 4,075 -78.75 0.0009
2024-02-15 2023-12-31 13F RAMBUS INC DEL COM 750917106 281,011 180,641 179.98 19,179 242.54 0.0050
2023-11-15 2023-09-30 13F RAMBUS INC DEL COM 750917106 100,370 19,926 24.77 5,600 8.47 0.0018
2023-08-14 2023-06-30 13F RAMBUS INC DEL COM 750917106 80,444 18,768 30.43 5,162 63.30 0.0017
2023-05-16 2023-03-31 13F RAMBUS INC DEL COM 750917106 61,676 -31,610 -33.89 3,162 -5.39 0.0013
2023-02-15 2022-12-31 13F RAMBUS INC DEL COM 750917106 93,286 74,774 403.92 3,342 609.34 0.0015
2022-11-15 2022-09-30 13F RAMBUS INC DEL COM 750917106 18,512 18,512 471 0.0002
2022-08-16 2022-06-30 13F RAMBUS INC DEL COM 750917106 0 -13,767 -100.00 0 -100.00
2022-05-17 2022-03-31 13F RAMBUS INC DEL COM 750917106 13,767 13,767 439 0.0001
2022-02-15 2021-12-31 13F RAMBUS INC DEL COM 750917106 0 -40,805 -100.00 0 -100.00
2021-11-16 2021-09-30 13F RAMBUS INC DEL COM 750917106 40,805 -5,152 -11.21 906 -16.88 0.0003
2021-08-16 2021-06-30 13F RAMBUS INC DEL COM 750917106 45,957 20,213 78.52 1,090 117.56 0.0004
2021-05-18 2021-03-31 13F RAMBUS INC DEL COM 750917106 25,744 13,146 104.35 501 127.73 0.0002
2021-02-17 2020-12-31 13F RAMBUS INC DEL COM 750917106 12,598 12,598 220 0.0001
2019-05-15 2019-03-31 13F RAMBUS INC DEL COM 750917106 0 -43,830 -100.00 0 -100.00
2019-02-14 2018-12-31 13F RAMBUS INC DEL COM 750917106 43,830 43,830 336 0.0007
2018-11-14 2018-09-30 13F RAMBUS INC DEL COM 750917106 0 -193,248 -100.00 0 -100.00
2018-08-15 2018-06-30 13F RAMBUS INC DEL COM 750917106 193,248 193,248 2,423 0.0057
2016-08-15 2016-06-30 13F RAMBUS INC DEL COM 750917106 0 -30,072 -100.00 0 -100.00
2016-05-17 2016-03-31 13F RAMBUS INC DEL COM 750917106 30,072 -4,150 -12.13 413 4.03 0.0023
2016-02-16 2015-12-31 13F RAMBUS INC DEL COM 750917106 34,222 18,271 114.54 397 111.17 0.0025
2015-11-16 2015-09-30 13F RAMBUS INC DEL COM 750917106 15,951 15,951 -53.39 188 -52.64 0.0012
2015-08-14 2015-06-30 13F RAMBUS INC DEL COM 750917106 0 -12,213 -100.00 0 -100.00
2015-05-11 2015-03-31 13F RAMBUS INC DEL COM 750917106 12,213 0 0.00 135 0.00 0.0010
2015-02-17 2014-12-31 13F RAMBUS INC DEL COM 750917106 12,213 -1,352 -9.97 135 -20.12 0.0010
2014-11-14 2014-09-30 13F RAMBUS INC DEL COM 750917106 13,565 13,565 169 0.0017
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
(%)
2026-05-12 2026-03-31 13F RAMBUS INC DEL COM Call 110,000 397.74 9,463 366.16 n/a n/a n/a
2026-02-12 2025-12-31 13F RAMBUS INC DEL COM Call 22,100 -85.09 2,031 -86.85 n/a n/a n/a
2025-11-14 2025-09-30 13F RAMBUS INC DEL COM Call 148,200 94.74 15,442 217.02 n/a n/a n/a
2025-08-14 2025-06-30 13F RAMBUS INC DEL COM Call 76,100 177.74 4,872 243.51 n/a n/a n/a
2025-05-19 2025-03-31 13F/A RAMBUS INC DEL COM Call 27,400 -43.27 1,419 -44.46 n/a n/a n/a
2025-05-14 2025-03-31 13F RAMBUS INC DEL COM Call 27,400 1,419 n/a n/a n/a
2025-02-14 2024-12-31 13F RAMBUS INC DEL COM Call 48,300 -1.02 2,553 23.93 n/a n/a n/a
2024-11-15 2024-09-30 13F RAMBUS INC DEL COM Call 48,800 13.75 2,060 -18.25 n/a n/a n/a
2024-08-15 2024-06-30 13F RAMBUS INC DEL COM Call 42,900 -33.69 2,521 -36.98 n/a n/a n/a
2024-05-16 2024-03-31 13F RAMBUS INC DEL COM Call 64,700 -35.30 3,999 -41.41 n/a n/a n/a
2024-02-15 2023-12-31 13F RAMBUS INC DEL COM Call 100,000 -12.43 6,825 7.13 n/a n/a n/a
2023-11-15 2023-09-30 13F RAMBUS INC DEL COM Call 114,200 -65.26 6,371 -69.79 n/a n/a n/a
2023-08-14 2023-06-30 13F RAMBUS INC DEL COM Call 328,700 1,225.40 21,093 1,559.48 n/a n/a n/a
2023-05-16 2023-03-31 13F RAMBUS INC DEL COM Call 24,800 -37.84 1,271 -11.06 n/a n/a n/a
2023-02-15 2022-12-31 13F RAMBUS INC DEL COM Call 39,900 -40.45 1,429 -16.09 n/a n/a n/a
2022-11-15 2022-09-30 13F RAMBUS INC DEL COM Call 67,000 35.63 1,703 60.36 n/a n/a n/a
2022-08-16 2022-06-30 13F RAMBUS INC DEL COM Call 49,400 -47.22 1,062 -64.42 n/a n/a n/a
2022-05-17 2022-03-31 13F RAMBUS INC DEL COM Call 93,600 -40.95 2,985 -35.92 n/a n/a n/a
2022-02-15 2021-12-31 13F RAMBUS INC DEL COM Call 158,500 5.32 4,658 39.42 n/a n/a n/a
2021-11-16 2021-09-30 13F RAMBUS INC DEL COM Call 150,500 -10.04 3,341 -15.78 n/a n/a n/a
2021-08-16 2021-06-30 13F RAMBUS INC DEL COM Call 167,300 183.08 3,967 245.26 n/a n/a n/a
2021-05-18 2021-03-31 13F RAMBUS INC DEL COM Call 59,100 4.42 1,149 16.30 n/a n/a n/a
2021-02-17 2020-12-31 13F RAMBUS INC DEL COM Call 56,600 -30.64 988 -11.55 n/a n/a n/a
2020-11-17 2020-09-30 13F RAMBUS INC DEL COM Call 81,600 67.56 1,117 50.95 n/a n/a n/a
2020-08-17 2020-06-30 13F RAMBUS INC DEL COM Call 48,700 740 n/a n/a n/a
2019-02-14 2018-12-31 13F RAMBUS INC DEL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-11-14 2018-09-30 13F RAMBUS INC DEL COM Call 25,000 273 n/a n/a n/a
2018-08-15 2018-06-30 13F RAMBUS INC DEL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-05-15 2018-03-31 13F RAMBUS INC DEL COM Call 14,300 192 n/a n/a n/a
2016-08-15 2016-06-30 13F RAMBUS INC DEL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2016-05-17 2016-03-31 13F RAMBUS INC DEL COM Call 39,400 183.45 542 236.65 n/a n/a n/a
2016-02-16 2015-12-31 13F RAMBUS INC DEL COM Call 13,900 -48.52 161 -49.53 n/a n/a n/a
2015-11-16 2015-09-30 13F RAMBUS INC DEL COM Call 27,000 319 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
(%)
2026-05-12 2026-03-31 13F RAMBUS INC DEL COM Put 53,100 22.07 4,568 14.29 n/a n/a n/a
2026-02-12 2025-12-31 13F RAMBUS INC DEL COM Put 43,500 -44.59 3,997 -51.13 n/a n/a n/a
2025-11-14 2025-09-30 13F RAMBUS INC DEL COM Put 78,500 24.60 8,180 102.80 n/a n/a n/a
2025-08-14 2025-06-30 13F RAMBUS INC DEL COM Put 63,000 -28.57 4,033 -11.67 n/a n/a n/a
2025-05-19 2025-03-31 13F/A RAMBUS INC DEL COM Put 88,200 4.38 4,567 2.24 n/a n/a n/a
2025-05-14 2025-03-31 13F RAMBUS INC DEL COM Put 88,200 4,567 n/a n/a n/a
2025-02-14 2024-12-31 13F RAMBUS INC DEL COM Put 84,500 195.45 4,467 270.01 n/a n/a n/a
2024-11-15 2024-09-30 13F RAMBUS INC DEL COM Put 28,600 652.63 1,207 441.26 n/a n/a n/a
2024-08-15 2024-06-30 13F RAMBUS INC DEL COM Put 3,800 -28.30 223 -31.80 n/a n/a n/a
2024-05-16 2024-03-31 13F RAMBUS INC DEL COM Put 5,300 -51.38 328 -55.99 n/a n/a n/a
2024-02-15 2023-12-31 13F RAMBUS INC DEL COM Put 10,900 -16.15 744 2.48 n/a n/a n/a
2023-11-15 2023-09-30 13F RAMBUS INC DEL COM Put 13,000 -44.68 725 -51.89 n/a n/a n/a
2023-08-14 2023-06-30 13F RAMBUS INC DEL COM Put 23,500 42.42 1,508 78.34 n/a n/a n/a
2023-05-16 2023-03-31 13F RAMBUS INC DEL COM Put 16,500 175.00 846 294.86 n/a n/a n/a
2023-02-15 2022-12-31 13F RAMBUS INC DEL COM Put 6,000 -61.29 215 -45.69 n/a n/a n/a
2022-11-15 2022-09-30 13F RAMBUS INC DEL COM Put 15,500 394 n/a n/a n/a
2022-08-16 2022-06-30 13F RAMBUS INC DEL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-05-17 2022-03-31 13F RAMBUS INC DEL COM Put 58,800 174.77 1,875 198.09 n/a n/a n/a
2022-02-15 2021-12-31 13F RAMBUS INC DEL COM Put 21,400 32.92 629 76.19 n/a n/a n/a
2021-11-16 2021-09-30 13F RAMBUS INC DEL COM Put 16,100 -1.83 357 -8.23 n/a n/a n/a
2021-08-16 2021-06-30 13F RAMBUS INC DEL COM Put 16,400 -33.06 389 -18.28 n/a n/a n/a
2021-05-18 2021-03-31 13F RAMBUS INC DEL COM Put 24,500 476 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.