Rambus Inc.
US ˙ NasdaqGS ˙ US7509171069

SecurityRMBS / Rambus Inc.
InstitutionRhumbline Advisers
Latest Disclosed Ownership319,580 shares
Latest Disclosed Value $ 27,493,436
Rhumbline Advisers reports 1.58% increase in ownership of RMBS / Rambus Inc.

On May 12, 2026 - Rhumbline Advisers filed a 13F-HR form disclosing ownership of 319,580 shares of Rambus Inc. (US:RMBS) valued at $27,493,467 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 314,612 shares of Rambus Inc.. This represents a change in shares of 1.58% during the quarter. The current value of the position is $46,438,170 USD.

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.

Upgrade to unlock premium data and export to Excel .

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 COM 750917106 319,580 4,968 1.58 27,493 -4.90 0.0235
2026-02-13 2025-12-31 13F RAMBUS INC DEL COM COM 750917106 314,612 -29,775 -8.65 28,910 -19.44 0.0234
2025-11-06 2025-09-30 13F RAMBUS INC DEL COM COM 750917106 344,387 -7,641 -2.17 35,885 59.23 0.0288
2025-08-12 2025-06-30 13F RAMBUS INC DEL COM COM 750917106 352,028 18,959 5.69 22,537 30.69 0.0193
2025-05-29 2025-03-31 13F/A-1 RAMBUS INC DEL COM COM 750917106 333,069 1,103 0.33 17,245 -1.73 0.0161
2025-04-08 2025-03-31 13F RAMBUS INC DEL COM COM 750917106 333,069 1,103 17,245 0.0161
2025-05-29 2024-12-31 13F/A-1 RAMBUS INC DEL COM COM 750917106 331,966 2,762 0.84 17,548 26.26 0.0157
2025-01-30 2024-12-31 13F RAMBUS INC DEL COM COM 750917106 331,966 2,762 17,548 0.0157
2024-11-12 2024-09-30 13F RAMBUS INC DEL COM COM 750917106 329,204 -11,433 -3.36 13,899 -30.56 0.0125
2024-08-01 2024-06-30 13F RAMBUS INC DEL COM COM 750917106 340,637 5,360 1.60 20,016 -3.42 0.0188
2024-05-09 2024-03-31 13F RAMBUS INC DEL COM COM 750917106 335,277 3,236 0.97 20,723 -8.55 0.0199
2024-02-08 2023-12-31 13F RAMBUS INC DEL COM COM 750917106 332,041 19,690 6.30 22,662 30.04 0.0238
2023-11-09 2023-09-30 13F RAMBUS INC DEL COM COM 750917106 312,351 386 0.12 17,426 -12.95 0.0202
2023-08-08 2023-06-30 13F RAMBUS INC DEL COM COM 750917106 311,965 -4,124 -1.30 20,019 125,012.50 0.0224
2023-05-11 2023-03-31 13F RAMBUS INC DEL COM COM 750917106 316,089 11,587 3.81 16 -99.85 0.0200
2023-02-14 2022-12-31 13F RAMBUS INC DEL COM COM 750917106 304,502 2,697 0.89 10,907 42.17 0.0147
2022-11-10 2022-09-30 13F RAMBUS INC DEL COM COM 750917106 301,805 14,381 5.00 7,672 24.20 0.0114
2022-08-11 2022-06-30 13F RAMBUS INC DEL COM COM 750917106 287,424 -8,235 -2.79 6,177 -34.49 0.0090
2022-05-12 2022-03-31 13F RAMBUS INC DEL COM COM 750917106 295,659 -4,451 -1.48 9,429 6.90 0.0121
2022-02-10 2021-12-31 13F RAMBUS INC DEL COM COM 750917106 300,110 -10,048 -3.24 8,820 28.09 0.0108
2021-11-12 2021-09-30 13F RAMBUS INC DEL COM COM 750917106 310,158 -50,213 -13.93 6,886 -19.41 0.0093
2021-08-05 2021-06-30 13F RAMBUS INC DEL COM COM 750917106 360,371 -13,046 -3.49 8,544 17.70 0.0112
2021-05-06 2021-03-31 13F RAMBUS INC DEL COM COM 750917106 373,417 -7,113 -1.87 7,259 9.26 0.0099
2021-02-10 2020-12-31 13F RAMBUS INC DEL COM COM 750917106 380,530 20,542 5.71 6,644 34.82 0.0092
2020-11-12 2020-09-30 13F RAMBUS INC DEL COM COM 750917106 359,988 -26,700 -6.90 4,928 -16.16 0.0077
2020-08-13 2020-06-30 13F RAMBUS INC DEL COM COM 750917106 386,688 -15,880 -3.94 5,878 31.53 0.0098
2020-05-06 2020-03-31 13F RAMBUS INC DEL COM COM 750917106 402,568 24,953 6.61 4,469 -14.09 0.0094
2020-02-05 2019-12-31 13F RAMBUS INC DEL COM COM 750917106 377,615 19,943 5.58 5,202 10.82 0.0087
2019-10-23 2019-09-30 13F RAMBUS INC DEL COM COM 750917106 357,672 24,615 7.39 4,694 17.06 0.0086
2019-08-14 2019-06-30 13F RAMBUS INC DEL COM COM 750917106 333,057 12,785 3.99 4,010 19.81 0.0075
2019-05-01 2019-03-31 13F RAMBUS INC DEL COM COM 750917106 320,272 3,468 1.09 3,347 37.74 0.0065
2019-01-31 2018-12-31 13F RAMBUS INC DEL COM COM 750917106 316,804 54,275 20.67 2,430 -15.15 0.0053
2018-11-07 2018-09-30 13F RAMBUS INC DEL COM COM 750917106 262,529 -723 -0.27 2,864 -13.24 0.0055
2018-08-06 2018-06-30 13F RAMBUS INC DEL COM COM 750917106 263,252 1,077 0.41 3,301 -6.25 0.0067
2018-05-02 2018-03-31 13F RAMBUS INC DEL COM COM 750917106 262,175 3,145 1.21 3,521 -4.40 0.0074
2018-02-09 2017-12-31 13F RAMBUS INC DEL COM COM 750917106 259,030 34,513 15.37 3,683 22.89 0.0075
2017-11-06 2017-09-30 13F RAMBUS INC DEL COM COM 750917106 224,517 2,990 1.35 2,997 18.36 0.0065
2017-08-02 2017-06-30 13F RAMBUS INC DEL COM COM 750917106 221,527 124 0.06 2,532 -12.96 0.0058
2017-05-02 2017-03-31 13F RAMBUS INC DEL COM COM 750917106 221,403 59,307 36.59 2,909 30.33 0.0068
2017-01-27 2016-12-31 13F RAMBUS INC DEL COM COM 750917106 162,096 -4,164 -2.50 2,232 7.41 0.0057
2016-11-08 2016-09-30 13F RAMBUS INC DEL COM COM 750917106 166,260 7,060 4.43 2,078 8.06 0.0057
2016-08-11 2016-06-30 13F RAMBUS INC DEL COM COM 750917106 159,200 15,079 10.46 1,923 -2.98 0.0057
2016-05-02 2016-03-31 13F RAMBUS INC USD.00 COM 750917106 144,121 420 0.29 1,982 19.04 0.0061
2016-02-03 2015-12-31 13F RAMBUS INC USD.00 COM 750917106 143,701 31,200 27.73 1,665 25.38 0.0054
2015-11-04 2015-09-30 13F RAMBUS INC USD.00 COM 750917106 112,501 3,414 3.13 1,328 -16.00 0.0045
2015-08-04 2015-06-30 13F RAMBUS INC USD.00 COM 750917106 109,087 -3,825 -3.39 1,581 11.34 0.0050
2015-05-12 2015-03-31 13F RAMBUS INC USD.00 COM 750917106 112,912 16,600 17.24 1,420 32.96 0.0041
2015-02-06 2014-12-31 13F RAMBUS INC USD.00 COM 750917106 96,312 -5,705 -5.59 1,068 -16.10 0.0031
2014-11-12 2014-09-30 13F RAMBUS INC USD.00 COM 750917106 102,017 -3,060 -2.91 1,273 -15.30 0.0038
2014-08-06 2014-06-30 13F RAMBUS INC USD.00 COM 750917106 105,077 -613 -0.58 1,503 32.31 0.0044
2014-05-06 2014-03-31 13F RAMBUS INC USD.00 COM 750917106 105,690 -5,440 -4.90 1,136 7.98 0.0034
2014-02-03 2013-12-31 13F RAMBUS INC USD.00 COM 750917106 111,130 -680 -0.61 1,052 0.10 0.0031
2013-11-05 2013-09-30 13F RAMBUS INC USD.00 COM 750917106 111,810 3,126 2.88 1,051 12.53 0.0033
2013-08-07 2013-06-30 13F RAMBUS INC USD.00 COM 750917106 108,684 108,684 934 0.0030
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.