Joshua T. Mook, Chief Technology Officer of Hyliion Holdings Corp. (NYSE:HYLN), filed a Form 4 on August 21, 2026, disclosing the disposition of 10,700 shares of common stock at $3.33 per share on the same date.

Key Highlights

  • Reporting person: Joshua T. Mook, Chief Technology Officer of Hyliion Holdings Corp.
  • Shares disposed: 10,700 shares of common stock, coded as Transaction Code J, on 08/21/2026
  • Price per share: $3.33
  • Beneficial ownership following transaction: 1,096,606 shares held directly
  • Nature of transaction: Shares were sold at the direction of the issuer to cover the reporting person's tax withholding obligations under the issuer's award agreement

Hyliion Holdings CTO Mook's Tax Withholding Share Sale Detailed

According to the filing, Joshua T. Mook, serving as Chief Technology Officer of Hyliion Holdings Corp. (NYSE:HYLN), reported a disposition of 10,700 shares of common stock on August 21, 2026, at a price of $3.33 per share. The transaction was assigned Transaction Code J in the filing, and the shares were disposed of directly.

The filing includes an explanation of the transaction's nature. As stated in the footnote: "These shares were sold at the direction of the issuer under the terms of the issuer's award agreement with the reporting person. Under the award agreement, the decision to sell shares to cover the reporting person's tax withholding obligations is at the sole discretion of the issuer." This indicates the disposition was not a discretionary open-market sale initiated by Mook, but rather a company-directed transaction tied to equity award administration.

Following the reported transaction, Mook's direct beneficial ownership of Hyliion Holdings common stock stood at 1,096,606 shares, according to the filing. No derivative securities transactions were reported in Table II of the form. The filing was made by one reporting person and is not identified as an amendment to a prior filing.

What Was Disclosed

Hyliion Holdings Corp.'s Chief Technology Officer, Joshua T. Mook, disclosed the issuer-directed disposition of 10,700 common shares at $3.33 each on August 21, 2026, for tax withholding purposes, leaving him with 1,096,606 directly held shares.