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RMBS · Rambus Inc

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Market Cap
$9.30B
Shares
108.14M

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 622
Total Value: $13,709,953,415
Total Shares: 103,440,585
Showing 1–100 of 647 holdings by value · page 1 of 7

Institutional Ownership Trend

26 quarters

Holder Concentration

Across 622 13F filers · Δ vs Mar 31, 2026
Top Holder
13.5%
Sep 2023 → Jun 2026 · range 13.5% – 18.8%
−2.2 pts
Top 5
40.7%
Sep 2023 → Jun 2026 · range 37.3% – 46.2%
+3.3 pts
Top 10
53.6%
Sep 2023 → Jun 2026 · range 50.9% – 57.9%
+2.6 pts
HHI
450
Sep 2023 → Jun 2026 · range 443 – 628
Broadly held+7

Quarterly Activity

vs Mar 31, 2026
New
140
Increased
190
Decreased
228
Sold Out
77
Unchanged
64
Holder count: +63
Institutional value: +54.0%
Shares held: -0.1%

Top Buyers

vs Mar 31, 2026
Institution Added Now Holds Open

Top Sellers

vs Mar 31, 2026
Institution Sold Now Holds Open

Top New Positions

vs Mar 31, 2026
Institution Acquired Value (USD) Open

Top Sold-Out Positions

vs Mar 31, 2026
Institution Previously Held Last Value (USD) Open
Showing 100 of 647
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Holder Value (USD) % of 13F Shares Open
Key facts CIK 917273 CUSIP 750917106 13F (30d) 444 filings 428 filers Visit website Investor relations