Twist Bioscience (TWST) CEO Reports Sell-to-Cover and Details Large Option Holdings

Rhea-AI Filing Summary

Emily M. Leproust, CEO and Director of Twist Bioscience (TWST), reported a non-discretionary sale and her current holdings. The filing shows a sale of 1,704 shares of Twist common stock on 09/22/2025 at $27.56 per share performed to satisfy tax-withholding required under the company's equity plans. After that transaction she beneficially owns 633,036 shares directly. The form also lists outstanding employee stock options with exercise prices and post-transaction holdings: $5.95 (0), $8.82 (150,879), $26.66 (266,539), $23.33 (131,290) and $67.85 (64,950). The filing notes one set of performance stock options vested and became exercisable on 12/19/2022.

Positive

• Sale was non-discretionary and executed solely to satisfy tax-withholding on vested RSUs, as stated in the filing
• Clear disclosure of option holdings and vesting history, including a performance tranche that vested on 12/19/2022

Negative

• Insider sold shares (1,704 shares) even though the filing clarifies it was to cover taxes
• Significant outstanding option exposure with large share counts at multiple strike prices that could dilute equity upon exercise

Insights

Financial Analyst

TL;DR: Insider completed a small, mandated sell-to-cover for RSU taxes; substantial option positions remain outstanding.

The Form 4 documents a sale of 1,704 shares at $27.56 on 09/22/2025 explicitly to cover tax withholding tied to RSU vesting, not a discretionary trade. The report confirms direct beneficial ownership of 633,036 shares and large option grants outstanding across multiple strike prices totaling several hundred thousand underlying shares. From an analytical perspective, the filing primarily updates ownership and exercise exposures rather than indicating a change in strategic ownership or control.

Corporate Governance Expert

TL;DR: Transaction is routine and plan-driven; disclosure aligns with Section 16 reporting requirements.

The sale is described as a company-mandated "sell to cover" to satisfy tax obligations associated with vested restricted stock units, which the filing explicitly states. The form includes full schedules of outstanding options and confirms a performance-based tranche vested on 12/19/2022. Filing is properly signed by an attorney-in-fact and provides clear descriptions of vesting schedules where applicable, meeting typical governance transparency expectations for insider reporting.

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

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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).

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)
09/22/2025

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	09/22/2025		S		1,704(1)	D	$27.56	633,036	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 Restricted Stock Units. 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	09/24/2025
	** 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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FAQ

What did Emily M. Leproust report on Form 4 for TWST?

The filing reports a sale of 1,704 shares on 09/22/2025 at $27.56 per share to satisfy tax-withholding and lists current beneficial ownership and option holdings.

Why were shares sold by the reporting person on 09/22/2025?

The filing states the shares were sold to cover tax withholding obligations arising from the vesting of Restricted Stock Units under the issuer's equity plans.

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

After the reported sale, the filing shows direct beneficial ownership of 633,036 shares.

What employee stock options does the Form 4 disclose for the reporting person?

The form lists options with exercise prices and post-transaction holdings: $5.95 (0), $8.82 (150,879), $26.66 (266,539), $23.33 (131,290), and $67.85 (64,950).

Did any performance-based awards vest according to the filing?

Yes. The filing notes performance stock options granted on 09/01/2020 that vested and became exercisable on 12/19/2022.