A Form 4 filed with the SEC on September 4, 2026, discloses that Christopher D. Brown, a director of 908 Devices Inc. (NASDAQ:MASS), sold 30,000 shares of common stock on September 2, 2026, under a pre-established Rule 10b5-1 trading plan.

Key Highlights

  • Reporting person: Christopher D. Brown, identified as a Director of 908 Devices Inc.
  • Transaction date: September 2, 2026, with 30,000 shares of common stock disposed of (transaction code S).
  • Weighted average price: $10.58 per share, with individual sales ranging from $10.33 to $10.97 inclusive.
  • Post-transaction ownership: Brown directly beneficially owns 775,559 shares of common stock following the reported transaction.
  • 10b5-1 plan: The sale was made pursuant to a Rule 10b5-1 trading plan adopted by Brown on November 24, 2025.
  • Filing agent: The form was signed by Mark S. Levine as Attorney-in-Fact on September 4, 2026.

908 Devices Director Reports Common Stock Sale via Pre-Scheduled Trading Plan

According to the filing, Christopher D. Brown, a director of 908 Devices Inc., sold 30,000 shares of the company's common stock on September 2, 2026. The transaction is coded "S" (a sale) and is reported as a direct disposal. The filing indicates the transaction was executed under a Rule 10b5-1 trading plan that Brown adopted on November 24, 2025, meaning the sale parameters were set in advance of the transaction date.

The filing discloses a weighted average sale price of $10.58 per share. Because the shares were sold across multiple transactions, the per-share price varied, with a reported range of $10.33 to $10.97 inclusive. The filing notes that Brown "undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote." Following the reported sale, Brown directly holds 775,559 shares of 908 Devices common stock, according to the filing.

No derivative securities transactions were reported in Table II of the filing. The Form 4 was filed on behalf of Brown by Mark S. Levine, Attorney-in-Fact, and carries a signature date of September 4, 2026. The filing also indicates, via a checked box, that the transaction qualifies under the affirmative defense conditions of Rule 10b5-1(c).

What Was Disclosed

The filing reports a single sale of 30,000 shares of 908 Devices common stock by director Christopher D. Brown on September 2, 2026, at a weighted average price of $10.58, conducted under a 10b5-1 plan adopted November 24, 2025, leaving Brown with 775,559 shares directly held.