Joshua T. Mook - 13 Nov 2025 Form 4 Insider Report for Hyliion Holdings Corp. (HYLN)

Signature
/s/ Joshua T. Mook
Issuer symbol
HYLN
Transactions as of
13 Nov 2025
Transactions value $
-$34,484
Form type
4
Filing time
17 Nov 2025, 19:28:48
Previous filing
29 Aug 2025
Next filing
01 Dec 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
MOOK JOSHUA T. Chief Technology Officer C/O HYLIION HOLDING CORP., 1202 BMC DRIVE, SUITE 100, CEDAR PARK /s/ Joshua T. Mook 2025-11-17 0002011297

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction HYLN Common Stock Tax liability -$6.9K -4.11K -0.78% $1.68 524K 13 Nov 2025 Direct F1
transaction HYLN Common Stock Tax liability -$12.6K -7.4K -1.41% $1.70 517K 14 Nov 2025 Direct F1
transaction HYLN Common Stock Other -$15K -9.04K -1.75% $1.66 508K 17 Nov 2025 Direct F2, F3
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 Shares withheld for the payment of a tax liability related to the vesting and distribution of restricted stock units.
F2 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.
F3 This transaction includes the sale of issuer common shares to cover the reporting person's tax withholding obligation for vesting dates on August 25, 2025. As a result of an administrative error by the issuer's third-party service provider, cash was paid on behalf of the reporting person for tax withholding obligations on the vesting date, August 25, 2025. A corresponding sale of issuer common shares to cover the reporting person's tax withholding obligation on August 25, 2025 could not be completed until the opening of the issuer's next window period. Accordingly, the the above shares attributed to the vesting on August 25, 2025 were sold November 17, 2025, the first available date during an open window period on which the shares could be sold on behalf of the reporting person.