Ranked by reported Q2 2026 13F market value
Share of total reported institutional value in RMBS held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 14.0M | $1.85B | -14.4% | 12.875% | 0.03% |
| 2 | FMR LLC | 10.5M | $1.39B | +215.2% | 9.644% | 0.06% |
| 3 | Invesco Ltd. | 6.6M | $880.4M | +2.1% | 6.115% | 0.07% |
| 4 | VANGUARD PORTFOLIO MANAGEMENT LLC | 6.1M | $805.5M | -8.7% | 5.595% | 0.04% |
| 5 | VANGUARD CAPITAL MANAGEMENT LLC | 4.9M | $647.0M | +1.0% | 4.494% | 0.01% |
| 6 | STATE STREET CORP | 3.9M | $519.5M | -10.5% | 3.610% | 0.01% |
| 7 | GEODE CAPITAL MANAGEMENT, LLC | 2.3M | $305.1M | -26.5% | 2.118% | 0.02% |
| 8 | JPMORGAN CHASE & CO | 2.1M | $261.0M | +14.4% | 1.938% | 0.01% |
| 9 | DIMENSIONAL FUND ADVISORS LP | 1.7M | $228.2M | -4.2% | 1.585% | 0.04% |
| 10 | Swedbank AB | 1.6M | $218.6M | +5.3% | 1.518% | 0.19% |
| 11 | NORGES BANK | 1.5M | $203.4M | — | 1.413% | 0.02% |
| 12 | MORGAN STANLEY | 1.4M | $191.7M | +19.1% | 1.332% | 0.01% |
| 13 | Neuberger Berman Group LLC | 1.3M | $173.4M | +0.7% | 1.209% | 0.06% |
| 14 | BANK OF AMERICA CORP /DE/ | 1.2M | $161.8M | -10.5% | 1.124% | 0.01% |
| 15 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 1.2M | $154.1M | +140.6% | 1.070% | 0.01% |
| 16 | AQR CAPITAL MANAGEMENT LLC | 1.2M | $152.5M | -3.1% | 1.117% | 0.05% |
| 17 | PointState Capital LP | 1.1M | $147.9M | +58.9% | 1.027% | 1.89% |
| 18 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 1.1M | $147.2M | -16.4% | 1.023% | 0.02% |
| 19 | EdgePoint Investment Group Inc. | 1.1M | $144.2M | -44.2% | 1.002% | 1.09% |
| 20 | JANE STREET GROUP, LLC | 1.1M | $143.0M | +539.4% | 0.993% | 0.01% |
| 21 | Rafferty Asset Management, LLC | 984K | $130.7M | +32.0% | 0.908% | 0.30% |
| 22 | GOLDMAN SACHS GROUP INC | 961K | $127.5M | +4.2% | 0.886% | 0.01% |
| 23 | NORTHERN TRUST CORP | 949K | $126.0M | -28.9% | 0.875% | 0.01% |
| 24 | CITADEL ADVISORS LLC | 878K | $116.5M | +646.4% | 0.809% | 0.01% |
| 25 | Bank of New York Mellon Corp | 828K | $109.9M | +6.2% | 0.764% | 0.02% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in RMBS — a direct measure of their conviction.
Filings activity in RMBS during Q2 2026, grouped by how each filer changed its position.
Institutions that opened a new RMBS position in Q2 2026
Institutions that fully closed their RMBS position in Q2 2026
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q2 2026 | 626 | +13% | 95.13% | 0.43 pp | $12.87B | +58% |
| Q1 2026 | 555 | +1.8% | 95.56% | +2.58 pp | $8.15B | 4.6% |
| Q4 2025 | 545 | +7.5% | 92.98% | 0.62 pp | $8.54B | 12% |
| Q3 2025 | 507 | +13% | 93.60% | +2.51 pp | $9.66B | +66% |
| Q2 2025 | 448 | +11% | 91.09% | +1.45 pp | $5.82B | +29% |
| Q1 2025 | 403 | +5.8% | 89.64% | +0.54 pp | $4.53B | 0.9% |
| Q4 2024 | 381 | +3.8% | 89.10% | +3.18 pp | $4.57B | +25% |
| Q3 2024 | 367 | — | 85.92% | — | $3.66B | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying RMBS stock.
Based on Q2 2026 13F filings, institutional ownership of Rambus Inc. stands at 95.1%, held across 626 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of RMBS, with approximately 13,964,477 shares worth $1.85B as of Q2 2026.
Yes — 3 widely-followed marquee investors appear among the top 25 institutional holders of RMBS, including SUSQUEHANNA INTERNATIONAL GROUP, LLP, JANE STREET GROUP, LLC, CITADEL ADVISORS LLC.
Our composite Smart Money Score for RMBS is 65 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
132 institutions opened new positions in RMBS during Q2 2026, while 68 fully exited. 394 added to existing positions and 79 trimmed.
RMBS institutional ownership fell by 0.43 percentage points quarter-over-quarter, with a net change of +71 holders.
The top 10 institutions account for 55.2% of all reported 13F value in RMBS, and the top 25 account for 72.6%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Rambus Inc. (RMBS) Institutional Ownership