Rambus Inc.
US ˙ NasdaqGS ˙ US7509171069

SecurityRMBS / Rambus Inc.
InstitutionLord, Abbett & Co. Llc
Latest Disclosed Ownership387,119 shares
Latest Disclosed Value $ 33,304
Lord, Abbett & Co. Llc reports 28.18% decrease in ownership of RMBS / Rambus Inc.

On May 14, 2026 - Lord, Abbett & Co. Llc filed a 13F-HR form disclosing ownership of 387,119 shares of Rambus Inc. (US:RMBS) valued at $33,303,848 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 539,028 shares of Rambus Inc.. This represents a change in shares of -28.18% during the quarter. The current value of the position is $56,252,262 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.

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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 387,119 -151,909 -28.18 33 -32.65 0.1087
2026-02-13 2025-12-31 13F RAMBUS INC DEL COM 750917106 539,028 -207,648 -27.81 50 -36.36 0.1519
2025-11-13 2025-09-30 13F RAMBUS INC DEL COM 750917106 746,676 428,354 134.57 78 285.00 0.2316
2025-08-14 2025-06-30 13F RAMBUS INC DEL COM 750917106 318,322 -23,664 -6.92 20 17.65 0.0656
2025-05-13 2025-03-31 13F RAMBUS INC DEL COM 750917106 341,986 341,986 18 0.0631
2024-11-14 2024-09-30 13F Rambus COM 750917106 0 -284,896 -100.00 0 -100.00
2024-10-07 2024-06-30 13F/A-1 Rambus COM 750917106 284,896 -476,577 -62.59 17 -65.96 0.0548
2024-08-14 2024-06-30 13F Rambus COM 750917106 284,896 -476,577 17 0.0559
2024-10-07 2024-03-31 13F/A-1 Rambus COM 750917106 761,473 -1,738,165 -69.54 47 -72.35 0.1519
2024-05-09 2024-03-31 13F Rambus COM 750917106 761,473 -1,738,165 47 0.1547
2024-10-07 2023-12-31 13F/A-1 Rambus COM 750917106 2,499,638 978,484 64.33 171 102.38 0.5987
2024-02-12 2023-12-31 13F Rambus COM 750917106 2,499,638 978,484 171 0.6126
2024-10-07 2023-09-30 13F/A-1 Rambus COM 750917106 1,521,154 -520,353 -25.49 85 -35.88 0.3155
2023-11-13 2023-09-30 13F Rambus COM 750917106 1,521,154 -520,353 85 0.3180
2024-10-07 2023-06-30 13F/A-1 Rambus COM 750917106 2,041,507 114,949 5.97 131 33.67 0.4510
2023-08-14 2023-06-30 13F Rambus COM 750917106 2,041,507 114,949 131 0.4510
2024-10-07 2023-03-31 13F/A-1 Rambus COM 750917106 1,926,558 -171,307 -8.17 99 30.67 0.3561
2023-05-12 2023-03-31 13F Rambus COM 750917106 1,926,558 -171,307 99 0.3566
2024-10-07 2022-12-31 13F/A-1 Rambus COM 750917106 2,097,865 -228 -0.01 75 -99.86 0.2685
2023-02-10 2022-12-31 13F Rambus COM 750917106 2,097,865 -228 75 0.2691
2022-11-14 2022-09-30 13F RAMBUS INC DEL COM COM 750917106 2,098,093 242,562 13.07 53,333 33.75 0.1948
2022-08-12 2022-06-30 13F RAMBUS INC DEL COM COM 750917106 1,855,531 -105,999 -5.40 39,876 -36.25 0.1410
2022-05-13 2022-03-31 13F RAMBUS INC DEL COM COM 750917106 1,961,530 236,164 13.69 62,553 23.36 0.1668
2022-02-11 2021-12-31 13F RAMBUS INC DEL COM COM 750917106 1,725,366 958,709 125.05 50,709 197.94 0.1155
2021-11-09 2021-09-30 13F RAMBUS INC DEL COM COM 750917106 766,657 -9,907 -1.28 17,020 -7.56 0.0407
2021-08-11 2021-06-30 13F RAMBUS INC DEL COM COM 750917106 776,564 -73,939 -8.69 18,412 11.36 0.0444
2021-05-11 2021-03-31 13F RAMBUS INC DEL COM COM 750917106 850,503 293,537 52.70 16,534 70.02 0.0421
2021-02-09 2020-12-31 13F RAMBUS INC DEL COM COM 750917106 556,966 113,323 25.54 9,725 60.14 0.0257
2020-11-12 2020-09-30 13F RAMBUS INC DEL COM COM 750917106 443,643 -27,563 -5.85 6,073 -15.21 0.0194
2020-08-14 2020-06-30 13F RAMBUS INC DEL COM COM 750917106 471,206 -249,637 -34.63 7,162 -10.49 0.0251
2020-05-14 2020-03-31 13F RAMBUS INC DEL COM COM 750917106 720,843 172,465 31.45 8,001 5.92 0.0354
2020-02-14 2019-12-31 13F RAMBUS INC DEL COM COM 750917106 548,378 548,378 7,554 0.0252
2016-02-16 2015-12-31 13F RAMBUS INC DEL COM COM 750917106 0 -1,666,871 -100.00 0 -100.00
2015-11-16 2015-09-30 13F RAMBUS INC DEL COM COM 750917106 1,666,871 -2,635,993 -61.26 19,669 -68.45 0.0593
2015-08-14 2015-06-30 13F RAMBUS INC DEL COM COM 750917106 4,302,864 1,922,090 80.73 62,348 108.26 0.1644
2015-05-15 2015-03-31 13F RAMBUS INC DEL COM COM 750917106 2,380,774 -526,044 -18.10 29,938 -7.13 0.0758
2015-02-13 2014-12-31 13F Rambus COM 750917106 2,906,818 -651,535 -18.31 32,237 -27.41 0.0817
2014-11-14 2014-09-30 13F Rambus COM 750917106 3,558,353 -14,484 -0.41 44,408 -13.08 0.1114
2014-08-20 2014-06-30 13F/A-1 RAMBUS INC DEL COM COM 750917106 3,572,837 3,572,837 51,092 0.1160
2014-08-14 2014-06-30 13F RAMBUS INC DEL COM COM 750917106 3,572,837 51,092 0.1170
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.