RMBS Institutional Ownership
Who owns Rambus Inc and what the big funds did with it last quarter, from every SEC 13F filing. 623 funds reported holding RMBS at Jun 30, 2026, together owning 94.0% of the company.
- ●322 buying vs 297 selling
- ▼Held by funds -2.0 pts
- ▲Funds holding +62
- ▲Superinvestors: 3 added, 1 cut
- ▲Put/call 0.26 to 0.15
What the filings show, not a forecast. Positions can be up to 45 days old and leave out short sales.
Funds holding and ownership
8 quartersQuarter over quarter
all 13F filers| Q2 2026 | This quarter | Q1 2026 | Change |
|---|---|---|---|
| Funds holding | 623 | 561 | +11.1% |
| In funds' top 10 | 2 | 2 | 0.0% |
| 13F shares | 101M | 103M | −2.1% |
| Held by funds | 94.0% | 96.0% | −2.0 pts |
| New positions | 132 | 73 | +80.8% |
| Increased | 190 | 188 | +1.1% |
| Reduced | 230 | 208 | +10.6% |
| Sold out | 67 | 76 | −11.8% |
| Calls (shares) | 636K | 34K | +1776.7% |
| Puts (shares) | 94K | 8,900 | +956.2% |
| Put/call ratio | 0.15 | 0.26 | −43.7% |
Buyers vs sellers
adding or new vs cutting or sold outSuperinvestors in RMBS
All superinvestors →
Who owns RMBS
share of fund held shares- Index and passive funds42.7%
- Active managers and hedge funds39.7%
- Banks and brokers13.5%
- Pensions, insurers and other4.1%
The top 10 holders own 55.0% of all RMBS shares that funds reported. Groups are our own grouping of filers by name.
Put/call ratio
funds' options, market makers left outAbove 1 means funds hold more puts than calls, a sign of hedging or bets on a fall. Options are valued at the underlying shares.
Filed so far for Q3 2026
199 funds changed their position- Congress Asset Management CoTrimmed−421K sh
- Mackenzie Financial CorpTrimmed−229K sh
- Principal Financial Group IncTrimmed−182K sh
- Daiwa Securities Group Inc.Added+179K sh
- Mirae Asset Global Investments Co., Ltd.Trimmed−141K sh
🔒 Free account: see all 20.
Top holders
Q2 2026| # | Fund | Of company | Shares | Value | Change |
|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 13.04% | 14M | $1.9B | −2.3M |
| 2 | Fmr LLC | 9.77% | 10.5M | $1.4B | +7.1M |
| 3 | Invesco Ltd. | 6.19% | 6.6M | $880M | +133K |
| 4 | Vanguard Portfolio Management LLC | 5.67% | 6.1M | $806M | −576K |
| 5 | Vanguard Capital Management LLC | 4.55% | 4.9M | $647M | +47K |
| 6 | State Street Corp | 3.66% | 3.9M | $519M | −459K |
| 7 | Price T Rowe Associates Inc /md/ | 3.11% | 3.3M | $443M | −42K |
| 8 | Geode Capital Management, LLC | 2.15% | 2.3M | $305M | −827K |
| 9 | Jpmorgan Chase & Co | 1.96% | 2.1M | $261M | +265K |
| 10 | Dimensional Fund Advisors LP | 1.61% | 1.7M | $228M | −76K |
- Fmr LLC+7.1M sh+$948M
- Norges Bank+1.5M sh+$203M
- D. E. Shaw & Co., Inc.+727K sh+$96.5M
- Manufacturers Life Insurance Company, the+695K sh+$92.2M
- Susquehanna International Group, LLP+470K sh+$62.4M
- Hrt Financial LP+423K sh+$56.2M
- Citadel Advisors LLC+384K sh+$50.9M
- Westfield Capital Management Co LP+371K sh+$49.3M
- BlackRock, Inc.−2.3M sh−$311M
- T. Rowe Price Investment Management, Inc.−2.4M sh−$206M
- EdgePoint Investment Group Inc.−862K sh−$114M
- Geode Capital Management, LLC−827K sh−$110M
- Voya Investment Management LLC−666K sh−$88.4M
- Ameriprise Financial Inc−654K sh−$86.8M
- UBS Group AG−583K sh−$77.4M
- Vanguard Portfolio Management LLC−576K sh−$76.4M
RMBS institutional ownership FAQ
Who owns the most RMBS stock?
In Q2 2026 13F filings the largest holder of RMBS was BlackRock, Inc., followed by Fmr LLC and Invesco Ltd.. Index fund managers are usually the biggest holders of large companies.
What percentage of RMBS is owned by institutions?
Funds that file 13F reports held 94.0% of RMBS's shares at Jun 30, 2026, compared with 96.0% a quarter earlier. That counts every manager with more than $100 million in US stocks.
Are hedge funds buying RMBS?
In Q2 2026, 322 funds bought RMBS (132 of them new positions) and 297 sold (67 sold out completely). Among well known investors, 3 added and 1 cut. Our fund sentiment for RMBS is bullish.
What is RMBS's institutional put/call ratio?
Funds reported $12.5M of RMBS puts against $84.4M of calls, a put/call ratio of 0.15 (0.26 the quarter before). Market makers and bank trading desks are left out, since their options are mostly hedges.
How current is this RMBS ownership data?
13F filings show holdings at the end of each quarter and are due within 45 days, so positions can be up to six weeks old when they appear. We add each new filing within minutes, and the "filed so far" list shows funds that have already reported the next quarter.
For informational and educational purposes only. Not investment advice, and not a recommendation to buy or sell any security. Fund sentiment summarises what 13F filings show and is not a forecast. Holdings come from SEC Form 13F filings as reported and show positions at the end of the quarter, up to 45 days before the filing. A 13F leaves out short positions, cash, bonds and most foreign holdings. See all hedge fund holdings.