Rambus Inc.
DE ˙ DB ˙ US7509171069
136,70 € ↑10,20 (8,06%)
2026-06-02
AKTIENPREIS
SecurityDE:RMB / Rambus Inc.
InstitutionSei Investments Co
Latest Disclosed Ownership386,745 shares
Latest Disclosed Value $ 35,537,992
Sei Investments Co ownership in RMB / Rambus Inc.

On February 13, 2026 - Sei Investments Co filed a 13F-HR form disclosing ownership of 386,745 shares of Rambus Inc. (DE:RMB) valued at $30,583,795 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 13, 2025 disclosing 280,553 shares of Rambus Inc.. This represents a change in shares of 37.85% during the quarter. The current value of the position is $52,868,041 USD.

Sei Investments Co has a history of taking positions in derivatives of the underlying security (RMB) in the form of stock options.

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.

DE:RMB / 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)
2026-02-13 2025-12-31 13F RAMBUS INC DEL COM 750917106 386,745 106,192 37.85 35,538 21.56 0.0351
2025-11-13 2025-09-30 13F RAMBUS INC DEL COM 750917106 280,553 -126,803 -31.13 29,234 12.10 0.0314
2025-08-14 2025-06-30 13F RAMBUS INC DEL COM 750917106 407,356 70,131 20.80 26,079 49.37 0.0302
2025-05-14 2025-03-31 13F/A-1 RAMBUS INC DEL COM 750917106 337,225 31,153 10.18 17,460 7.91 0.0225
2025-05-13 2025-03-31 13F RAMBUS INC DEL COM 750917106 307,539 1,467 16,240 0.0177
2025-02-11 2024-12-31 13F RAMBUS INC DEL COM 750917106 306,072 -37,032 -10.79 16,179 11.69 0.0208
2024-11-12 2024-09-30 13F RAMBUS INC DEL COM 750917106 343,104 58,162 20.41 14,486 -13.49 0.0188
2024-08-13 2024-06-30 13F RAMBUS INC DEL COM 750917106 284,942 94,462 49.59 16,743 42.22 0.0237
2024-05-07 2024-03-31 13F RAMBUS INC DEL COM 750917106 190,480 22,060 13.10 11,774 2.43 0.0173
2024-02-14 2023-12-31 13F RAMBUS INC DEL COM 750917106 168,420 -37,985 -18.40 11,495 -0.18 0.0185
2023-11-14 2023-09-30 13F RAMBUS INC DEL COM 750917106 206,405 3,974 1.96 11,515 -11.35 0.0207
2023-08-11 2023-06-30 13F RAMBUS INC DEL COM 750917106 202,431 34,495 20.54 12,991 50.89 0.0227
2023-05-12 2023-03-31 13F RAMBUS INC DEL COM 750917106 167,936 -50,580 -23.15 8,609 9.99 0.0160
2023-02-10 2022-12-31 13F RAMBUS INC DEL COM 750917106 218,516 137,528 169.81 7,827 280.14 0.0174
2022-11-14 2022-09-30 13F RAMBUS INC DEL COM 750917106 80,988 7,167 9.71 2,059 26.63 0.0046
2022-08-15 2022-06-30 13F RAMBUS INC DEL COM 750917106 73,821 -47,523 -39.16 1,626 -57.73 0.0035
2022-05-13 2022-03-31 13F RAMBUS INC DEL COM 750917106 121,344 18,232 17.68 3,847 25.27 0.0077
2022-02-14 2021-12-31 13F RAMBUS INC DEL COM 750917106 103,112 50,888 97.44 3,071 164.97 0.0058
2021-11-12 2021-09-30 13F RAMBUS INC DEL COM 750917106 52,224 -24,722 -32.13 1,159 -36.28 0.0024
2021-08-06 2021-06-30 13F RAMBUS INC DEL COM 750917106 76,946 57,468 295.04 1,819 408.10 0.0040
2021-05-12 2021-03-31 13F RAMBUS INC DEL COM 750917106 19,478 -10,674 -35.40 358 -32.20 0.0009
2021-02-08 2020-12-31 13F RAMBUS INC DEL COM 750917106 30,152 6,993 30.20 528 69.23 0.0014
2020-12-04 2020-09-30 13F/A-1 RAMBUS INC DEL COM 750917106 23,159 -323 -1.38 312 -12.61 0.0009
2020-11-06 2020-09-30 13F RAMBUS INC DEL COM 750917106 23,159 -323 312 751.2266
2020-08-17 2020-06-30 13F/A-1 RAMBUS INC DEL COM 750917106 23,482 -39,498 -62.72 357 -49.07 0.0011
2020-08-11 2020-06-30 13F RAMBUS INC DEL COM 750917106 20,772 -42,208 306 830.0413
2020-05-14 2020-03-31 13F RAMBUS INC DEL COM 750917106 62,980 43,644 225.71 701 159.63 0.0026
2020-02-06 2019-12-31 13F RAMBUS INC DEL COM 750917106 19,336 -461 -2.33 270 2.27 0.0008
2019-11-12 2019-09-30 13F RAMBUS INC DEL COM 750917106 19,797 6,499 48.87 264 63.98 0.0007
2019-08-14 2019-06-30 13F RAMBUS INC DEL COM 750917106 13,298 389 3.01 161 17.52 0.0005
2019-05-15 2019-03-31 13F RAMBUS INC DEL COM 750917106 12,909 3,036 30.75 137 69.14 0.0005
2019-02-13 2018-12-31 13F RAMBUS INC DEL COM 750917106 9,873 1,882 23.55 81 -7.95 0.0003
2018-11-08 2018-09-30 13F RAMBUS INC DEL COM 750917106 7,991 -9,674 -54.76 88 -60.18 0.0003
2018-08-03 2018-06-30 13F RAMBUS INC DEL COM 750917106 17,665 1,757 11.04 221 3.76 0.0008
2018-05-11 2018-03-31 13F RAMBUS INC DEL COM 750917106 15,908 -48,784 -75.41 213 -76.85 0.0008
2018-02-08 2017-12-31 13F RAMBUS INC DEL COM 750917106 64,692 -265 -0.41 920 5.99 0.0032
2017-11-06 2017-09-30 13F RAMBUS INC DEL COM 750917106 64,957 3,211 5.20 868 22.95 0.0031
2017-07-31 2017-06-30 13F RAMBUS INC DEL COM 750917106 61,746 -253 -0.41 706 -13.27 0.0028
2017-05-05 2017-03-31 13F RAMBUS INC DEL COM 750917106 61,999 -370 -0.59 814 -5.24 0.0036
2017-02-02 2016-12-31 13F RAMBUS INC DEL COM 750917106 62,369 -11,871 -15.99 859 -7.44 0.0042
2016-11-04 2016-09-30 13F RAMBUS INC DEL COM 750917106 74,240 60,930 457.78 928 480.00 0.0047
2016-08-11 2016-06-30 13F RAMBUS INC DEL COM 750917106 13,310 2,255 20.40 160 5.26 0.0010
2016-05-10 2016-03-31 13F/A-1 RAMBUS INC DEL COM 750917106 11,055 505 4.79 152 24.59 0.0009
2016-02-03 2015-12-31 13F RAMBUS INC DEL COM 750917106 10,550 -41,310 -79.66 122 -80.07 0.0007
2015-11-02 2015-09-30 13F/A-1 RAMBUS INC DEL COM 750917106 51,860 -71,473 -57.95 612 -65.75 0.0056
2015-10-30 2015-09-30 13F RAMBUS INC DEL COM 750917106 51,860 613
2015-08-07 2015-06-30 13F/A-1 RAMBUS INC DEL COM 750917106 123,333 -116 -0.09 1,787 15.14 0.0162
2015-08-04 2015-06-30 13F RAMBUS INC DEL COM 750917106 123,333 -116 1,787 0.0162
2015-05-14 2015-03-31 13F/A-1 RAMBUS INC DEL COM 750917106 123,449 -12,911 -9.47 1,552 2.65 0.0135
2015-05-01 2015-03-31 13F RADIO ONE PUT 750917106 123,449 123,449 1,552 0.0135
2015-02-10 2014-12-31 13F RAMBUS INC DEL COM 750917106 136,360 136,360 1,512 0.0134
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
(%)
2015-05-01 2015-03-31 13F RADIO ONE PUT 123,449 1,552 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.