---
title: "Rambus CEO Luc Seraphin Has Sold $21M in RMBS Stock — 10,000 Shares Per Week Like Clockwork"
type: news
slug: rambus-ceo-seraphin-21-million-career-insider-sales
canonical_url: https://13finsight.com/news/rambus-ceo-seraphin-21-million-career-insider-sales
published_at: 2026-03-01T18:13:53.843Z
updated_at: 2026-03-01T18:14:04.597Z
author: Alex Rivera
author_title: Breaking News Editor
author_url: https://13finsight.com/authors/alex-rivera
word_count: 297
locale: en
source: 13F Insight
---

# Rambus CEO Luc Seraphin Has Sold $21M in RMBS Stock — 10,000 Shares Per Week Like Clockwork

> Rambus CEO Luc Seraphin has sold $21M across 133 transactions with a clockwork pattern: 10,000 shares every week in April 2025 at $45-$59/share, while maintaining a 319K-share position.

Luc Seraphin, President and CEO of Rambus Inc (RMBS), has sold $21 million in company stock across 133 transactions with zero career purchases. His April 2025 selling pattern was mechanical precision: exactly 10,000 shares sold every Tuesday for five consecutive weeks at prices ranging from $45 to $59. The Numbers MetricValue Career Sell Value$21.0M Career Buy Value$0 Total Transactions133 Last Transaction2026-02-01 Shares Remaining319,241 Recent Activity DateTypeSharesPriceEst. Value 2025-04-23Sell6,348$46.9700$298K 2025-04-22Sell1,255$45.0000$56K 2025-04-15Sell10,000$47.7868$478K 2025-04-08Sell10,000$46.8100$468K 2025-04-01Sell10,000$50.8815$509K The weekly 10,000-share cadence is the clearest 10b5-1 plan signature in Seraphin's filing history. Each sale occurred on a Tuesday, suggesting a predetermined execution schedule. The price decline from $58.64 (March 25) to $45.00 (April 22) during the selling window means his plan executed through a 23% price drop without interruption — confirming these were automatic, not discretionary trades. What It Means Seraphin's selling profile is a textbook 10b5-1 plan in action. The identical lot sizes (10,000 shares), consistent day-of-week execution (Tuesdays), and continuation through adverse price moves all point to a pre-set disposition program. For Rambus investors, this pattern is actually the least alarming form of insider selling — it signals planned diversification, not discretionary timing. With 319,241 shares remaining (~$15M at recent prices), Seraphin maintains a substantial personal stake in Rambus. The company's pivot from patent licensing to silicon IP for data centers and AI infrastructure has positioned RMBS as a semiconductor picks-and-shovels play. A CEO who sells mechanically while retaining 15x his annual selling rate in shares is managing personal risk, not abandoning the company thesis. What to Watch Whether Seraphin's 10b5-1 plan resumes in 2026 after the April 2025 selling window Rambus's HBM and chiplet interface technology revenue trajectory Memory industry CapEx trends driving demand for Rambus silicon IP Any plan amendments that change the lot size or frequency of sales

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Source: 13F Insight — https://13finsight.com/news/rambus-ceo-seraphin-21-million-career-insider-sales
Author: Alex Rivera — https://13finsight.com/authors/alex-rivera
Last updated: 2026-03-01T18:14:04.597Z