---
title: Illumina Co-Founder David Walt Has Sold $114 Million in ILMN Stock — Now Buying Quanterix
type: news
slug: walt-ilmn-qtrx-114-million-career-insider-sales
canonical_url: https://13finsight.com/news/walt-ilmn-qtrx-114-million-career-insider-sales
published_at: 2026-03-01T17:34:24.856Z
updated_at: 2026-03-23T07:05:02.726Z
author: Alex Rivera
author_title: Breaking News Editor
author_url: https://13finsight.com/authors/alex-rivera
word_count: 337
locale: en
source: 13F Insight
---

# Illumina Co-Founder David Walt Has Sold $114 Million in ILMN Stock — Now Buying Quanterix

> David Walt, co-founder of Illumina's core bead array technology and director at Quanterix, has sold $114 million in ILMN stock across 4,807 transactions — while recently buying $1.4 million of QTRX shares.

David Walt, the scientist who co-invented the bead array technology at the heart of Illumina (ILMN), has filed 4,807 insider transactions totaling $114 million in career sales — but his most recent activity tells a different story: he’s buying heavily into Quanterix (QTRX). The Numbers MetricValue Career Sell Value$114.1M Career Buy Value$11.5M Total Transactions4,807 Last Transaction2026-01-02 Shares Remaining1,872,890 (QTRX) Recent Activity DateTypeSharesPriceEst. Value 2026-01-02Award1,215N/AN/A (QTRX) 2025-06-13Buy123,990$6.14$760,803 (QTRX) 2025-06-12Buy36,010$6.23$224,166 (QTRX) 2025-06-09Buy78,131$5.34$417,220 (QTRX) 2025-06-06Buy131,869$5.43$716,576 (QTRX) Walt's 2025 activity is exclusively Quanterix. In June 2025 alone, he purchased 370,000 QTRX shares for approximately $2.1 million at prices between $5.34 and $6.23 per share. These are open-market purchases — not option exercises — signaling high-conviction buying in a $5-6 stock. He also receives quarterly director stock awards, accumulating 1.87 million shares total. What It Means Walt is a Tufts University professor and one of the key inventors behind Illumina's bead-based DNA sequencing technology, which helped make Illumina the dominant force in genomics. His $114 million in ILMN sales across 4,807 transactions reflects decades of systematic liquidation as Illumina grew from a startup to a $20+ billion market cap company. The Quanterix pivot is notable: Walt is a co-founder and board member of the ultra-sensitive protein detection company (Simoa technology). His $1.4 million in open-market QTRX purchases at $5-6 per share — combined with 1.87 million shares — represents a significant bet on a company trading at a fraction of its 2021 highs above $70. For an insider who systematically sold $114M of one genomics company, his aggressive buying of another suggests strong conviction in Quanterix's single-molecule detection platform. What to Watch Whether Walt continues open-market QTRX purchases — his June 2025 buying spree was unusually aggressive for a director Quanterix's stock trajectory — trading near $5-6 versus 2021 highs above $70 creates significant upside potential if the business recovers Walt's remaining Illumina exposure (if any) — his Form 4 filings now show QTRX as his primary company The broader trend of biotech founders rotating capital from mature platforms to early-stage companies

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Source: 13F Insight — https://13finsight.com/news/walt-ilmn-qtrx-114-million-career-insider-sales
Author: Alex Rivera — https://13finsight.com/authors/alex-rivera
Last updated: 2026-03-23T07:05:02.726Z