Institutional ownership · Form 13F
RMBS institutional ownership
Rambus: reported institutional holdings as of 2026-06-30 (filed through 2026-08-31), aggregated by StockEyes from SEC Form 13F information tables. RMBS is one of 2732 tickers in the validated publication set. Mapping coverage in this publication set: 4562 of 6046 universe tickers have at least one validated CUSIP mapping (75.5%). Latest-quarter filed value resolved to any listed ticker: 77.3%; resolved to this universe: 77.2%.
RMBS: change since the prior quarter's filings
More managers reported a position, with the count rising from 551 in the quarter ended 2026-03-31 to 617 in the quarter ended 2026-06-30 (+66, 12.0%). Total reported shares fell to 100,657,787 (-2,075,274, 2.0%), against the direction of the manager count. Among the 24 managers listed as top holders in both quarters, the largest increases were FMR LLC (+7,141,577 shares) and JPMORGAN CHASE & CO (+264,918 shares), among 10 managers who added shares, and the largest decreases were BlackRock, Inc. (-2,340,829 shares) and EdgePoint Investment Group Inc. (-861,529 shares), among 14 managers who reduced shares. NORGES BANK (1,532,622 shares), MANUFACTURERS LIFE INSURANCE COMPANY, THE (797,195 shares) and 4 more entered the listed top holders; CITIGROUP INC (1,007,548 shares in the prior quarter), AMERIPRISE FINANCIAL INC (975,209 shares in the prior quarter) and 4 more dropped out of the listed top holders.
New to 13F data? Read how to read a 13F filing, or see where institutions moved overall in the Smart Money Report.
Reported totals, quarter ended 2026-06-30
617 reporting managers held 100,657,787 shares, reported value $12,507,208,170 exactly as filed. Values are position values transcribed from the filings, not current market prices.
Reported quarter-over-quarter change (quarter ended 2026-03-31 to quarter ended 2026-06-30): reporting managers +66, reported shares -2,075,274 (-2.02%), reported value +54.55%. These changes compare two filing snapshots.
Shares outstanding cross-check: no current issuer share-count point passed the freshness filter for this ticker, so the gate relied on holder-count and scale checks. See the hub methodology.
RMBS in this quarter's filings
Concentration check: the largest reported position, BlackRock, Inc. with 13,964,477 shares, is 13.9% of all shares reported for RMBS this quarter. The five largest reporting managers together account for 41.7% of the reported total, so the headline total is spread across a broad manager base rather than a few holders.
Reported quarter-over-quarter change: the reporting-manager count rose by 66 versus the quarter ended 2026-03-31, and reported shares moved -2.02% (-2,075,274 shares). That is a comparison of two filing snapshots, not a record of trades on any single day.
Shares-outstanding cross-check: no current issuer share-count point passed the freshness filter for RMBS, so the publication gate relied on holder-count scale, current-CUSIP validation, and quarter consistency for this ticker.
Largest reporting managers, RMBS
| # | Manager | Shares | Value as filed | Share of reported total |
|---|---|---|---|---|
| 1 | BlackRock, Inc. | 13,964,477 | $1,853,644,563 | 13.9% |
| 2 | FMR LLC | 10,460,026 | $1,388,463,915 | 10.4% |
| 3 | Invesco Ltd. | 6,632,458 | $880,392,476 | 6.6% |
| 4 | VANGUARD PORTFOLIO MANAGEMENT LLC | 6,068,516 | $805,534,814 | 6.0% |
| 5 | VANGUARD CAPITAL MANAGEMENT LLC | 4,874,385 | $647,025,865 | 4.8% |
| 6 | STATE STREET CORP | 3,915,113 | $519,498,009 | 3.9% |
| 7 | GEODE CAPITAL MANAGEMENT, LLC | 2,297,660 | $305,059,152 | 2.3% |
| 8 | JPMORGAN CHASE & CO | 2,101,418 | $260,985,471 | 2.1% |
| 9 | DIMENSIONAL FUND ADVISORS LP | 1,719,400 | $228,190,556 | 1.7% |
| 10 | Swedbank AB | 1,646,500 | $218,556,410 | 1.6% |
| 11 | NORGES BANK | 1,532,622 | $203,440,244 | 1.5% |
| 12 | MORGAN STANLEY | 1,444,281 | $191,714,297 | 1.4% |
| 13 | NEUBERGER BERMAN GROUP LLC | 1,311,777 | $173,445,614 | 1.3% |
| 14 | BANK OF AMERICA CORP /DE/ | 1,218,726 | $161,773,689 | 1.2% |
| 15 | AQR CAPITAL MANAGEMENT LLC | 1,211,009 | $152,478,080 | 1.2% |
Manager names and figures are transcribed from each manager's own Form 13F information table. A manager listing shares in this snapshot does not mean it holds them today.
Reported change, 2026-03-31 to 2026-06-30
| Quarter ended | Filed through | Reporting managers | Reported shares | Value as filed |
|---|---|---|---|---|
| 2026-03-31 | 2026-05-29 | 551 | 102,733,061 | $8,092,707,235 |
| 2026-06-30 | 2026-08-31 | 617 | 100,657,787 | $12,507,208,170 |
Every change figure on this page is a reported quarter-over-quarter change between filing snapshots. It is not real-time trading activity.
RMBS reported totals over time
Quarter ended 2026-06-30: 617 reporting managers · 100,657,787 reported shares · $12,507,208,170 value as filed.
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Quarter-end 13F filed data, long positions only; filings arrive up to 45 days after quarter end.
CUSIPs behind the RMBS total
The validated bridge mapped 1 current CUSIP(s) to RMBS for this quarter: 750917106. Option pseudo-CUSIPs, units, warrants, and preferred classes are excluded from these common-share totals. Mapping coverage in this publication set: 4562 of 6046 universe tickers have at least one validated CUSIP mapping (75.5%). Latest-quarter filed value resolved to any listed ticker: 77.3%; resolved to this universe: 77.2%.
What this page is and is not
Form 13F reports are quarterly holdings snapshots. Managers file up to about 45 days after quarter-end, so these figures describe reported positions as of the quarter-end date, not holdings today. 13F lists reportable long positions from managers above the SEC reporting threshold and omits short positions entirely.
This page is informational only. It is not investment advice, a recommendation, or a signal to buy or sell. Source: SEC Form 13F bulk data set for filings through 2026-08-31 (period ended 2026-06-30), joined to tickers through StockEyes' validated CUSIP bridge. Methodology and coverage are documented on the institutional ownership hub.
Insider transactions for RMBS (officer and director buys and sells) are covered by InsiderTrace: insidertrace.com/stock/rmbs. StockEyes does not duplicate insider transaction tables.
Related StockEyes pages
Latest headlines tagged RMBS are on the market news wire. Upcoming earnings and market dates are on the events calendar. The term itself is defined in the institutional investor glossary entry, and the research workflow behind pages like this one is walked through in how to research a stock and how to compare SEC filings.