Twist Bioscience (TWST) CAO executes small tax-related share sale

Rhea-AI Filing Summary

Twist Bioscience Corp’s Chief Accounting Officer, Robert F. Werner, reported an insider stock sale tied to tax withholding. On May 21, 2026, he sold 688 shares of common stock at $53.257 per share in an open-market transaction.

According to the footnote, the shares were sold solely to cover tax withholding obligations from vesting Restricted Stock Units under the company’s equity incentive plans, and did not represent discretionary trading. After this mandated “sell to cover” transaction, Werner directly holds 48,986 common shares of Twist Bioscience.

Insights

Equity analyst

Small, non‑discretionary tax sale; limited informational value.

The filing shows Chief Accounting Officer Robert F. Werner sold 688 Twist Bioscience shares at $53.257 per share. A footnote clarifies the sale was required to cover tax withholding on vesting Restricted Stock Units under the company’s equity incentive plans.

Because the transaction was a mandated “sell to cover” rather than a discretionary trade, it carries weak signaling value about Werner’s view of the stock. The 688 shares represent a small portion of his position, as he continues to hold 48,986 common shares directly after the sale.

Insider Trade Summary

Net Seller: 688 shares

Net Sell 1 txn

Insider WERNER ROBERT F.

Role Chief Accounting Officer

Sold 688 shs ($37K)

Type	Security	Shares	Price	Value
Sale	Common Stock	688	$53.257	$37K

Holdings After Transaction: Common Stock — 48,986 shares (Direct)

Footnotes (1)

1. F1. 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.

Key Figures

Shares sold: 688 shares Sale price per share: $53.257 per share Shares held after transaction: 48,986 shares +1 more

4 metrics

Shares sold 688 shares Open-market sale on May 21, 2026

Sale price per share $53.257 per share Tax-related sale to cover withholding

Shares held after transaction 48,986 shares Direct holdings of Robert F. Werner post-sale

Transaction type Sale in open market or private transaction Form 4 code S with tax-withholding footnote

Key Terms

Restricted Stock Units, sell to cover, equity incentive plans

3 terms

Restricted Stock Units financial

"in connection with the vesting of Restricted Stock Units."

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

sell to cover financial

"funded by a "sell to cover" transaction and do not represent"

Sell to cover is when a person who receives company stock through options or awards sells just enough shares immediately to pay required taxes, exercise costs, or fees, keeping the rest. Think of it like cashing part of a bonus to cover the tax bill so you can keep the remainder. For investors, it can create predictable small selling pressure and slightly change the number of shares actually held by insiders without increasing long‑term dilution.

equity incentive plans financial

"the Issuer's election under its equity incentive plans to require"

Equity incentive plans are company programs that pay employees, executives, or directors with company stock, stock options, or share units instead of or in addition to cash, aiming to align their interests with shareholders—like giving team members a stake in the house they help build. For investors this matters because such plans can motivate better company performance but also dilute existing ownership and increase reported compensation costs, so they affect future earnings, voting power, and share value.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Form 4 Insider Transactions: What Each Field Means →

Accepted by SEC EDGAR 05/26/2026 - 04:05 PM Learn about SEC filing dates

FAQ

What insider transaction did Twist Bioscience (TWST) report for Robert F. Werner?

Twist Bioscience reported that Chief Accounting Officer Robert F. Werner sold 688 common shares. The shares were sold at $53.257 each on May 21, 2026, as part of a mandated transaction to cover tax withholding tied to vesting Restricted Stock Units.

Why did Twist Bioscience (TWST) executive Robert F. Werner sell 688 shares?

The 688 shares were sold solely to cover tax withholding obligations from vesting Restricted Stock Units. The company’s equity incentive plans require a “sell to cover” transaction for taxes, so the sale was not a discretionary trade by Werner in the open market.

How many Twist Bioscience (TWST) shares does Robert F. Werner hold after this Form 4?

After the tax-related sale, Robert F. Werner directly holds 48,986 Twist Bioscience common shares. This indicates the 688 shares sold for tax withholding represent a small portion of his total position, and he retains a substantial remaining ownership stake.

At what price were the Twist Bioscience (TWST) shares sold in this insider transaction?

The 688 Twist Bioscience common shares were sold at an average price of $53.257 per share. This open-market transaction was executed to satisfy tax withholding obligations associated with vesting Restricted Stock Units under the company’s equity incentive plans.

Does Robert F. Werner’s Form 4 suggest a discretionary sale of Twist Bioscience (TWST) stock?

The Form 4 footnote states the sale was mandated as a “sell to cover” for tax withholding on Restricted Stock Units. Because it was required under equity incentive plan rules, it is not considered a discretionary decision to reduce his investment in Twist Bioscience.

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
Estimated average burden
hours per response:			0.5

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^*

WERNER ROBERT F.

(Last) (First) (Middle)

C/O TWIST BIOSCIENCE CORPORATION

681 GATEWAY BLVD

(Street)

SOUTH SAN FRANCISCO CALIFORNIA 94080

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/21/2026

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

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

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

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	05/21/2026		S		688(1)	D	$53.257	48,986	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

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.

Remarks:

	/s/ Kendra Fox, as Attorney-in-Fact for Robert F. Werner	05/26/2026
	** 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.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)