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AlphaScala
SEC Form 4 transaction code

Form 4 Code F: Shares Withheld for Tax

Code F marks shares delivered to or withheld by the company to pay an exercise price, or the tax due on stock from a Rule 16b-3 award.

“Payment of exercise price or tax liability by delivering or withholding securities incident to the receipt, exercise or vesting of a security issued in accordance with Rule 16b-3”
SEC Form 4, General Instruction 8 (Transaction Codes), under “Rule 16b-3 Transaction Codes”. Form 4 and instructions (PDF, sec.gov)

How often code F appears in real filings

Share of transaction rows
10.0%
4,987 of 50,023 rows, 4th most common
Filings with a code F row
18.6%
3,727 of 20,089 filings
Companies
883
of 2,099 in the sample
Median days, trade to filing
2
calendar days

4,955 of the rows are in Table I (non-derivative securities) and 32 in Table II (derivative securities).

Sample: 50,023 transaction rows in 20,089 Form 4 and 4/A filings filed Jul 23 – Oct 21, 2026 by insiders of 2,099 companies with an AlphaScala stock page. Rows are counted as filed; see how the codes are counted.

SEC Form 4 filings as of Oct 21, 2026

Reading code F on a Form 4

F is how net settlement shows up. When restricted stock vests, many companies keep enough of the new shares to cover the employee’s tax withholding and deliver the rest. The insider’s holdings fall by the withheld shares, but the insider does not sell them in the market.

The price on an F row is the per-share value used for the withholding, usually the market price around the vesting or exercise date, so shares times price gives the value of the tax or exercise price paid in stock. An F row normally sits on the same filing as the M or A rows for the award that triggered it.

Counting F rows as sales overstates insider selling. AlphaScala’s insider tables and cluster screen leave them out.

Code F in real filings

Recent Form 4 lines coded F, chosen from the newest filings in the sample, one company each. Figures are as filed; each links to the filing on sec.gov.

MUMICRON TECHNOLOGY INC

Filing on sec.gov
Insider
MEHROTRA SANJAY, President and CEO
Transaction date
Oct 13, 2026
Filed
Oct 15, 2026
Table
I, non-derivative
Shares
47,143
Price
$989.04
Shares × price
$46.6M
Held after
277,214 (direct)
  • MEHROTRA SANJAY (President and CEO) had 47,143 shares withheld or delivered to pay an exercise price or tax, valued at $989.04 per share, about $46.6M.
  • Shares held after the transaction: 277,214, held directly.
  • The same filing also reports 6 code M rows (471,332 shares and derivative securities), 5 code F rows (119,113 shares) and 4 code A rows (300,634 shares and derivative securities).
  • Filed 2 days after the transaction date.

FERGFerguson Enterprises Inc. /DE/

Filing on sec.gov
Insider
Murphy Kevin Michael, See Remarks
Transaction date
Oct 12, 2026
Filed
Oct 14, 2026
Table
I, non-derivative
Shares
14,232
Price
$220.04
Shares × price
$3.1M
Held after
181,096 (direct)
  • Murphy Kevin Michael (See Remarks) had 14,232 shares withheld or delivered to pay an exercise price or tax, valued at $220.04 per share, about $3.1M.
  • Shares held after the transaction: 181,096, held directly.
  • The Rule 10b5-1 box is checked on this filing: a transaction on it was made under a plan intended to meet Rule 10b5-1(c).
  • The same filing also reports 3 code A rows (21,855 shares) and 1 code S row (11,259 shares).
  • Filed 2 days after the transaction date.

REGNREGENERON PHARMACEUTICALS, INC.

Filing on sec.gov
Insider
MURPHY ANDREW J, Co-Chief Scientific Officer
Transaction date
Oct 13, 2026
Filed
Oct 15, 2026
Table
I, non-derivative
Shares
12,853
Price
$754.58
Shares × price
$9.7M
Held after
51,980 (direct)
  • MURPHY ANDREW J (Co-Chief Scientific Officer) had 12,853 shares withheld or delivered to pay an exercise price or tax, valued at $754.58 per share, about $9.7M.
  • Shares held after the transaction: 51,980, held directly.
  • The Rule 10b5-1 box is checked on this filing: a transaction on it was made under a plan intended to meet Rule 10b5-1(c).
  • The same filing also reports 27 code S rows (4,147 shares) and 2 code M rows (34,000 shares and derivative securities).
  • Filed 2 days after the transaction date.

Codes read alongside F

Questions about these codes

How common is code F on Form 4?

In AlphaScala’s sample of 50,023 Form 4 transaction rows filed Jul 23 – Oct 21, 2026, code F made up 10.0% of rows (4,987) and appeared on 18.6% of filings (3,727 of 20,089). It was the 4th most common of the 16 codes found.

Is a code F transaction a sale?

Not in the market. Code F is "payment of exercise price or tax liability by delivering or withholding securities", so the shares go to the company to settle a tax bill or an exercise price. The insider receives no cash for them; their value pays the tax or the exercise price.

Why does code F appear when stock vests?

In the US, restricted stock and units are generally taxed as income when they vest, and companies often withhold part of the shares to cover the tax. The withheld shares are reported on Form 4 with code F, usually on the same filing as the vesting.

How is code F different from code D?

Both send shares to the company. F is limited to paying an exercise price or tax incident to a Rule 16b-3 award. D is a "disposition to the issuer of issuer equity securities pursuant to Rule 16b-3(e)", such as shares the company buys back from an officer or director.

Definition: SEC Form 4, General Instruction 8 (sec.gov). Examples and counts: AlphaScala's copy of SEC EDGAR Form 4 filings. See all 20 Form 4 transaction codes, insider cluster buys and our methodology.

Educational reference only, not investment advice. Insider transactions have many motives and a Form 4 does not record them. See our risk disclaimer.