Mackay Sean 4

What Happened

• Sean Mackay, SVP & Chief Business Officer of Standard BioTools (ticker: LAB), had 25,729 shares withheld/disposed to satisfy tax withholding obligations tied to the vesting of restricted stock units (RSUs). The withholding was recorded at $1.00 per share for a total of $25,729.

Key Details

• Transaction date: 2026-05-20; Form 4 filed: 2026-05-22 (appears timely).
• Price reported: $1.00 per share; total value: $25,729.
• Transaction code: F — shares withheld to cover tax liability (not an open-market sale).
• Shares owned after the transaction: not specified in the provided filing.
• Footnote: The withheld shares relate to RSUs granted on May 20, 2024; March 21, 2025; and March 20, 2026 (original grants reported on prior Forms 3/4).

Context

• This was a tax-withholding disposition (routine). Such withholdings are common when RSUs vest and do not necessarily signal insider sentiment about the company’s stock.
• For retail investors: purchases are typically more informative than routine withholdings; this entry reflects compensation tax mechanics rather than a deliberate investment decision.