Rambus
RMBS
553 hedge funds and large institutions have $9.18B invested in Rambus in 2025 Q4 according to their latest regulatory filings, with 103 funds opening new positions, 189 increasing their positions, 195 reducing their positions, and 54 closing their positions.
91% more first-time investments, than exits
New positions opened: 103 | Existing positions closed: 54
40% more call options, than puts
Call options by funds: $65.1M | Put options by funds: $46.4M
8% more funds holding
Funds holding: 513 → 553 (+40)
0.93% more ownership
Funds ownership: 91.78% → 92.71% (+0.93%)
3% less repeat investments, than reductions
Existing positions increased: 189 | Existing positions reduced: 195
11% less capital invested
Capital invested by funds: $10.3B → $9.18B (-$1.11B)
50% less funds holding in top 10
Funds holding in top 10: 6 → 3 (-3)
Top Buyers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
Invesco
Atlanta,
Georgia
|
+$169M |
| 2 |
DCM
Driehaus Capital Management
Chicago,
Illinois
|
+$93.9M |
| 3 |
BlackRock
New York
|
+$45.9M |
| 4 |
Fisher Asset Management
Camas,
Washington
|
+$35.9M |
| 5 |
Public Sector Pension Investment Board (PSP Investments)
Montreal,
Quebec, Canada
|
+$30M |
Top Sellers
| Rank | Fund | Capital Flow |
|---|---|---|
| 1 |
EIG
EdgePoint Investment Group
Toronto,
Ontario, Canada
|
-$126M |
| 2 |
ACM
Analog Century Management
New York
|
-$65.8M |
| 3 |
Bank of New York Mellon
New York
|
-$49.6M |
| 4 |
JP Morgan Chase
New York
|
-$48.4M |
| 5 |
Vanguard Group
Malvern,
Pennsylvania
|
-$40.4M |
RMBS Hedge Fund Activity: Q4 2025 in Review
553 of the 8,266 institutional investors tracked by Wall St. Rank reported a position in Rambus (RMBS) for Q4 2025, worth a combined $9.18B — down 11% from $10.3B a quarter earlier.
Buyers outnumbered sellers: 103 funds opened new RMBS positions and 54 closed out — a net gain of 49 holders — while 189 added to existing stakes and 195 trimmed.
The largest buyer was Invesco, adding an estimated $169M. The largest seller was EdgePoint Investment Group, cutting an estimated $126M.
- 553 institutional investors held Rambus (RMBS) as of Q4 2025, up from 513 in Q3 2025.
- Funds reported $9.18B of Rambus stock for Q4 2025, down 11% quarter-over-quarter.
- 103 funds opened new Rambus positions in Q4 2025 and 54 closed out, a net change of +49 holders.
- The largest Rambus buyer in Q4 2025 was Invesco, an estimated $169M added.
- The largest Rambus seller in Q4 2025 was EdgePoint Investment Group, an estimated $126M sold.
Based on aggregated 13F filings for Q4 2025.