Twist Bioscience CEO sells 31,348 shares to cover taxes

Rhea-AI Filing Summary

Insider sale to cover tax withholding following PSU vesting. The Form 4 shows Twist Bioscience Corp (TWST) Chief Executive Officer and Director Emily M. Leproust reported a sale of 31,348 shares on 10/06/2025 at a price of $32.187 per share. The filing states the sale was a mandated "sell to cover" to satisfy tax-withholding obligations tied to vesting Performance Stock Units, not a discretionary trade. After the transaction, the Reporting Person beneficially owns 601,212 shares and holds multiple outstanding employee stock options totaling reported option counts, including 64,950 exercisable shares from a performance grant.

Positive

• Sale was a mandatory "sell to cover" tied to PSU tax withholding, not a discretionary trade
• Substantial remaining ownership: reporting person retains 601,212 shares after the transaction
• Existing vested options: holds 64,950 exercisable shares from a performance grant

Negative

• Immediate dilution risk: sale of 31,348 shares increased current free float by that amount
• Potential future share supply: multiple outstanding options 600,000 reported in tables) could be exercised over time

Insights

Corporate Insider / Compensation Analyst

Mandatory sell-to-cover after PSU vesting reduced holdings by 31,348 shares.

The sale is described as required by the issuer's election under its equity plans to satisfy tax withholding for vested Performance Stock Units, which means the transaction is an administrative liquidity event rather than a discretionary sale.

The reporting shows continued substantial ownership of 601,212 shares and several outstanding options, including 64,950 vested performance options; monitor future scheduled vesting or option exercises over the next 12 months for additional share supply.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Leproust Emily M.

(Last) (First) (Middle)

C/O TWIST BIOSCIENCE CORPORATION

681 GATEWAY BLVD.

(Street)

SOUTH SAN FRANCISCO CA 94080

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Twist Bioscience Corp [ TWST ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
10/06/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	10/06/2025		S		31,348(1)	D	$32.187	601,212	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (right to buy)	$5.95							(2)	09/28/2025	Common Stock	0		0	D
Employee Stock Option (right to buy)	$8.82							(3)	09/28/2027	Common Stock	0		150,879	D
Employee Stock Option (right to buy)	$26.66							(4)	11/18/2028	Common Stock	0		266,539	D
Employee Stock Option (right to buy)	$23.33							(5)	10/23/2029	Common Stock	0		131,290	D
Employee Stock Option (right to buy)	$67.85							12/19/2022	08/31/2030	Common Stock	64,950		64,950(6)	D

Explanation of Responses:

1. Represents the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of Performance Stock Units ("PSUs"). These sales are mandated by the Issuer's election under its equity incentive plans to require the satisfaction of a tax withholding obligation to be funded by a "sell to cover" transaction and do not represent discretionary trades by the Reporting Person.

2. The option is immediately exercisable. 25% of the shares subject to the option vested on September 1, 2016 and 1/48th of the shares subject to the option vest on each monthly anniversary thereafter, subject to the Reporting Person's continuous service through each vesting date.

3. The option is immediately exercisable. 10% of the shares subject to the option vested on September 28, 2017, 15% of the shares subject to the option vested on September 28, 2018, and 1/48th of the shares subject to the option vest on each monthly anniversary thereafter, subject to the Reporting Person's continuous service through each vesting date.

4. 20% of the shares subject to the option vested and became exercisable on October 31, 2019 and 1/60th of the shares subject to the option vest and become exercisable on each monthly anniversary thereafter, subject to the Reporting Person's continuous service through each vesting date.

5. 25% of the shares subject to the option vested on October 24, 2020, and 1/48th of the shares subject to the option vest on each monthly anniversary thereafter, subject to the Reporting Person's continuous service through each vesting date.

6. Represents performance stock options granted to the reporting person on September 1, 2020, that vested and became exercisable on December 19, 2022 as a result of the reporting person having met the applicable performance criteria.

Remarks:

	/s/ Kendra Fox, as Attorney-in-Fact for Emily M. Leproust	10/08/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

What did TWST insider Emily Leproust sell on 10/06/2025?

She sold 31,348 shares at $32.187 per share on 10/06/2025 to cover tax-withholding from vested PSUs.

Was the 10/06/2025 sale a discretionary trade by the CEO of TWST?

No. The filing states the sale was a mandated "sell to cover" under the company's equity plan to satisfy tax withholding and not a discretionary sale.

How many TWST shares does Emily Leproust beneficially own after the transaction?

She beneficially owns 601,212 shares following the reported transaction.

Does the Form 4 show any vested options for the reporting person?

Yes. The filing shows 64,950 vested and exercisable performance options and additional outstanding options with later exercisable dates.

Are there any dates to watch for additional vesting or exercises?

The filing lists option exercisable and expiration dates, including exercisable options that vested on 12/19/2022 and other awards with exercisable dates through 2030.