RMBS Insider Trading

Rambus Inc. (RMBS) operates in the Technology sector, specifically the Semiconductors industry, with a market capitalization near $10.65B, listed on NASDAQ, employing roughly 791 people, carrying a beta of 1.85 to the broader market. Rambus Inc. Led by Luc Seraphin, public since 1997-05-14.

In the last 12 months, Rambus Inc. insiders made 0 buy transactions and 32 sale transactions.

DateNameTypeSharesPriceValue
Oct 5, 2026KISSNER CHARLESS-Sale5,000$111.00$555.0K
Sep 24, 2026KISSNER CHARLESS-Sale5,000$105.00$525.0K
Sep 15, 2026Taulbee William Clarence II0$0.00$0
Aug 10, 2026KISSNER CHARLESS-Sale5,000$100.92$504.6K
Jun 3, 2026Sayiner NecipS-Sale5,000$170.15$850.8K
Jun 3, 2026Higashi EmikoS-Sale5,000$163.00$815.0K
Jun 3, 2026Higashi EmikoS-Sale5,000$158.00$790.0K
Jun 2, 2026STANG ERIC BS-Sale5,000$146.00$730.0K
May 27, 2026Higashi EmikoS-Sale5,000$157.57$787.9K
May 26, 2026FAN XIANZHI SEANS-Sale37,814$151.69$5.7M

RMBS Insider Activity by Quarter

Reported Form 4 and Form 5 lines under RMBS's own SEC company ID, by transaction date, back to Q4 2024. Purchases and sales are code P / S (open market or private) in the company's shares; other lines are purchases and sales of other securities (options, warrants, preferred), awards, exercises, tax withholding, gifts and other acquisitions and dispositions. Later filings and amendments can change the current quarter. Earlier quarters are not shown: the filings read reach back to Mar 26, 2018, and a quarter counts only when every filing for it was read.

QuarterPurchasesBoughtSalesSoldOther Lines
Q4 2026 (so far)0N/A1$555.0K0
Q3 20260N/A2$1.0M0
Q2 20260N/A15$13.3M19
Q1 20260N/A12$5.2M9
Q4 20250N/A5$1.9M2
Q3 20250N/A8$2.6M1
Q2 20250N/A9$2.5M17
Q1 20250N/A7$6.0M8
Q4 20240N/A2$458.0K0

RMBS Institutional Ownership (13F)

As of Jun 30, 2026 (Q2 2026), 617 institutions reported holding 100,657,787 RMBS shares, valued at $13.30B as reported, 107.3% of its market cap (market cap of Jun 26, 2026). That is +60 institutions from the quarter before. Among managers whose reports for both quarters are comparable, 124 opened a position, 60 closed one, 189 added and 227 trimmed.

Top Holders, Q2 2026

ManagerSharesValueChange
BlackRock, Inc.13,964,477$1.85B-2,340,829
FMR LLC10,460,026$1.39B+7,141,577
Invesco Ltd.6,632,458$880.4M+133,410
VANGUARD PORTFOLIO MANAGEMENT LLC6,068,516$805.5M-575,804
VANGUARD CAPITAL MANAGEMENT LLC4,874,385$647.0M+46,531
STATE STREET CORP3,915,113$519.5M-458,504
PRICE T ROWE ASSOCIATES INC /MD/3,334,512$442.6M-42,177
GEODE CAPITAL MANAGEMENT, LLC2,297,660$305.1M-826,835
JPMORGAN CHASE & CO2,101,418$261.0M+264,918
DIMENSIONAL FUND ADVISORS LP1,719,400$228.2M-75,895

By Quarter

QuarterInstitutionsSharesValue
Q2 2026617100,657,787$13.30B
Q1 2026557102,793,511$8.83B
Q4 202555499,910,185$9.19B
Q3 2025512101,310,946$10.56B
Q2 202545797,368,428$6.23B
Q1 202540795,789,169$5.01B
Q4 202439095,021,378$5.02B
Q3 202437295,808,627$4.06B
Q2 2024359103,830,281$6.10B

From the SEC's Form 13F data sets: investment managers with $100 million or more in Section 13(f) securities report their holdings each quarter, up to 45 days after it ends; a restated filing replaces the original, and values are as the managers reported them (a position whose price runs about 1,000 times below other managers', from a manager whose positions mostly do, is read as reported in thousands of dollars). The same shares can be reported by more than one manager, so totals can count some twice.

ETFs Holding RMBS

FundWeight of RMBSShares (as reported)Value (as reported)Source updated
XSD State Street SPDR S&P Semiconductor ETF2.91%840,456$95.5MOct 8, 2026
MDY State Street SPDR S&P MIDCAP 400 ETF Trust0.35%809,079$91.6MOct 8, 2026
IWP iShares Russell Mid-Cap Growth ETF0.34%605,850$67.5MOct 8, 2026
SPMD State Street SPDR Portfolio S&P 400 Mid Cap ETF0.36%580,299$65.6MOct 8, 2026
SCHA Schwab U.S. Small-Cap ETF0.30%571,994$64.4MOct 8, 2026
IWR iShares Russell Mid-Cap ETF0.09%444,224$49.5MOct 8, 2026
IWF iShares Russell 1000 Growth ETF0.03%403,811$45.0MOct 8, 2026
ARTY iShares Future AI & Tech ETF0.94%366,526$40.9MOct 8, 2026
SCHM Schwab U.S. Mid-Cap ETF0.25%325,673$37.2MOct 7, 2026
DFAC Dimensional - US Core Equity 2 ETF0.03%243,141$27.7MOct 8, 2026
JQUA JPMorgan U.S. Quality Factor ETF0.29%236,127$26.4MOct 5, 2026
TMSL T. Rowe Price Small-Mid Cap ETF0.83%226,660$25.9MOct 8, 2026
MDYG State Street SPDR S&P 400 Mid Cap Growth ETF0.68%174,549$19.8MOct 8, 2026
FTEC Fidelity MSCI Information Technology Index ETF0.08%173,872$19.4MOct 8, 2026
ITOT iShares Core S&P Total U.S. Stock Market ETF0.02%142,875$15.9MOct 8, 2026

From each fund's latest holdings file on record that shows RMBS's listed security itself. A file counts when its line count is consistent with the fund's reported holdings count (at most twice it plus 10, or at most 1,000 lines for a reported count of exactly 10, which the data source gives many funds as a cap), read with that file or inherited from the fund's last classified file (within 20% of its line count, read within 60 days). Funds whose line for the company could not be confirmed as RMBS's listed security, or that hold it through underlying funds (look-through), are not listed. Only long positions count: a fund is left out when any of its lines for RMBS reports a negative weight, share count or value, or none of them above zero (a short position, or figures that disagree). Shares, value and weight are as reported in each fund's file, dated by the data source's last update of that file (not the date of the positions); the weight is RMBS's share of that fund.

RMBS Congress Trades

Members of Congress and their households disclosed 1 transaction in RMBS on file (0 purchases, 1 sales) by 1 member, the latest trade on Aug 10, 2023.

MemberChamberTypeAmountTradedDisclosed
Thomas R. Carper (D-DE)SenateSale (Full)$1,001 - $15,000Aug 10, 2023Sep 4, 2023

From the periodic transaction reports members of the Senate and the House file under the STOCK Act, within 45 days of a trade (some file later); amounts are the ranges the reports give (a few give an exact amount), and a transaction a later report lists again is counted once. On file: House reports disclosed from Apr 10, 2023 through Oct 13, 2026; Senate reports disclosed from Jan 30, 2014 through Oct 7, 2026. The party is the member's on the trade date. A trade is listed under the company that traded under its ticker on the trade date (dated from Feb 1, 2021, unless the filing describes another company of ours; before that, only when the filing's description of the security is the company's name).

How to Read RMBS Insider Activity

Net insider sentiment skews to the sell side over the trailing twelve months: 32 sales versus 0 buys. Insider sales carry less informational weight than buys because they are often driven by liquidity, tax planning, or pre-scheduled Rule 10b5-1 trading plans rather than negative information. The transaction type alone does not say whether a sale was made on the open market or privately, or under a 10b5-1 plan; the filing's plan checkbox and footnotes do. The transaction table above includes the filer's reporting name, transaction type, share count, per-share price, and total dollar value where computable. For options traders, insider activity is one input to event-driven sizing alongside earnings calendar, analyst-rating cluster moves, and the implied-vol surface. Form 4 filings (the dominant Section 16 reporting form) must be submitted within two business days of the transaction; clusters of buys across multiple insiders within a short window are the strongest informational pattern. SEC EDGAR carries the underlying source filings for verification and additional historical depth.

Learn how insider trading is reported and how to read the data →

Frequently asked RMBS insider trading questions

How active are RMBS insiders right now?
Over the trailing twelve months, Rambus Inc. (RMBS) insiders made 0 buy transactions and 32 sale transactions. Net insider sentiment over the trailing twelve months tilts to the sell side (32 sales vs 0 buys). The transaction list above shows the most recent filings; each entry includes the insider's name, transaction type, share count, and per-share price.
What counts as an insider transaction?
Section 16 of the Securities Exchange Act requires officers, directors, and 10% beneficial-owner shareholders to disclose changes in their holdings via Form 3 (initial statement), Form 4 (subsequent transactions, filed within two business days), and Form 5 (annual catch-up). Insider transactions cover open-market purchases and sales, exercise of stock options, gifts, and grants. The "transaction type" field on each row distinguishes these subcategories.
Are RMBS insider buys a bullish signal?
Insider purchases (Type P, made on the open market or privately; the code covers both) carry more informational weight than insider sales: an insider must commit personal capital, and the SEC scrutinizes purchases under Rule 10b5-1 for material non-public information. Sales, by contrast, are often driven by liquidity, tax planning, or pre-scheduled 10b5-1 trading plans rather than negative information. Cluster buying (multiple insiders buying within a short window) is a stronger signal than isolated buys.
How do RMBS insider transactions affect options pricing?
Insider transaction data does not directly drive implied volatility, but Form 4 disclosures can move single-name IV if the size or timing is unusual (e.g. a large CEO buy ahead of an earnings window). Options markets price the marginal informational content; routine transactions under pre-scheduled plans are typically ignored. For event-driven options sizing, pair the insider transaction history with the upcoming earnings calendar.