John Cox

John Cox, listed as chief executive, has filed trades across 3 companies (mainly through SEC (Form 4)), most often in Dyne Therapeutics, Inc., Biogen Inc. and Sigilon Therapeutics, Inc. Between 8 February 2016 and 8 September 2026, the trades on record add up to 16 filings.

In open-market terms, that means 2 purchases worth €804k on one side and 9 sales worth €463k on the other. The totals do not cover 1 filing with an undisclosed amount. A purchase on the market is a deliberate choice to commit personal money, which is why it draws more attention than a grant. Other entries cover 3 share grants and 1 option exercise. In 2026 alone, the filings show no purchases and 5 sales.

The latest filing, published on 8 September 2026, reports an open-market sale of €92k in Dyne Therapeutics, Inc. The most recent open-market purchase was published on 15 July 2025, 460 days ago. The median gap between a trade and its publication by SEC (Form 4) is 1 day. The legal deadline for a Form 4 is two business days after the transaction. A sale on its own says little: insiders also sell to pay tax, fund a purchase or diversify. Every figure here comes from the filings published by SEC (Form 4) and describes the past, not future prices; it is not investment advice.