Hawryluk P. Kent 4

4 · MBX Biosciences, Inc. · Filed May 8, 2026

AI-generated summary of this filing

Updated May 8, 2026

MBX Biosciences CEO P. Kent Hawryluk Sells 607 Shares

What Happened

P. Kent Hawryluk, President & CEO and Director of MBX Biosciences (MBX), sold 607 shares of common stock on 2026-05-06. The weighted average sale price reported is $29.54 per share, for aggregate proceeds of approximately $17,931.
This transaction was a sale executed to cover tax obligations associated with the vesting of restricted stock units (RSUs), a routine sell-to-cover action rather than an outright investment decision.

Key Details

Transaction date: 2026-05-06; Form 4 filed: 2026-05-08 (appears timely — within the typical 2 business day window).
Price: $29.54 weighted average; reported sale prices ranged from $29.23 to $29.88. The filer offers to provide the per-price breakdown on request.
Shares sold: 607; Proceeds: ~$17,931.
Shares held after transaction: Not specified in the provided summary.
Footnotes of note:
- Mandatory sell-to-cover to satisfy tax withholding on RSU vesting.
- Weighted-average price with a disclosed range ($29.23–$29.88); detailed per-price breakdown available on request.
- Some shares are held by a revocable trust of which the reporting person is trustee; the filer disclaims beneficial ownership of those trust shares except to the extent of any pecuniary interest.

Context

Sell-to-cover transactions are common when RSUs vest; they are used solely to pay tax withholding and are generally considered routine rather than a signal about the insider’s view of the company.
For retail investors, purchases are usually more informative about insider confidence than routine sales to cover taxes.

Form 4

Period: 2026-05-06

DirectorPresident & CEO

Transactions

Holdings

Footnotes (3)

[F1]The sales reported on this Form 4 represent shares of common stock sold by the Reporting Person to cover tax obligations in connection with the vesting of restricted stock units, pursuant to a mandatory sell-to-cover agreement between the Reporting Person and the Company.
[F2]The price reported in Column 4 is a weighted average price. These shares were sold on an aggregrate basis for all Company participants, at prices ranging from $29.23 to $29.88, inclusive. The Reporting Person 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 aggregrate number of shares sold at each separate price within the range set forth in this footnote.
[F3]Shares held by the P. Kent Hawryluk Revocable Trust dated January 25, 2011, of which the Reporting Person serves as trustee. The Reporting Person disclaims beneficial ownership except to the extent of any pecuniary interest therein, and this report shall not be deemed an admission that such shares are beneficially owned by him for Section 16 or any other purpose.

Signature

/s/ P. Kent Hawryluk|2026-05-08

1 file