[Form 4] BICYCLE THERAPEUTICS PLC Insider Trading Activity

Rhea-AI Filing Summary

Bicycle Therapeutics PLC (BCYC) reported two insider sales by Chief Technology Officer Michael Skynner tied to restricted stock unit vesting. On 10/02/2025 he sold 824 ordinary shares at a weighted average price of $8.40 and on 10/03/2025 he sold 978 shares at a weighted average price of $8.41.

The filings state these were mandatory "sell-to-cover" transactions executed to satisfy statutory tax withholding required by his award agreement rather than discretionary sales. After the transactions his direct beneficial ownership is reported as 118,277 ordinary shares.

Insights

Corporate Governance Analyst

TL;DR: Insider sold shares to satisfy tax withholding from RSU vesting; transactions were routine, not discretionary.

The sales by the Chief Technology Officer are described as "sell-to-cover" actions tied to restricted stock unit settlement, meaning the company-mandated mechanism converted a portion of vested shares to cash to meet tax obligations. The filing lists weighted average prices of $8.40 and $8.41 on 10/02/2025 and 10/03/2025, respectively.

Because the sales are non-discretionary under the award agreement, this reduces the typical governance concern that an insider is selling for personal reasons; however, the reported direct ownership falling to 118,277 shares is a concrete change investors can track in future filings over the next 12 months for further insider activity.

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^*

Skynner Michael

(Last) (First) (Middle)

C/O BICYCLE THERAPEUTICS PLC

BLOCKS A & B, PORTWAY BUILDING

(Street)

CAMBRIDGE X0 CB21 6GS

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BICYCLE THERAPEUTICS PLC [ BCYC ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF TECHNOLOGY OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
10/02/2025

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
Ordinary Shares	10/02/2025		S		824(1)	D	$8.4(2)	119,255	D
Ordinary Shares	10/03/2025		S		978(1)	D	$8.41(3)	118,277	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 to cover the statutory tax withholding obligations in connection with the vesting and settlement of restricted stock units. This sale is mandated by the Reporting Person's award agreement that requires the satisfaction of minimum statutory tax withholding obligations to be funded by a "sell to cover" transaction and does not represent a discretionary sale by the Reporting Person.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $8.31 to $8.45 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) and (3).

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $8.40 to $8.50 inclusive.

	/s/ Travis Thompson, Attorney-in-Fact	10/06/2025
	** 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.
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.

FAQ

What did Bicycle Therapeutics (BCYC) insider Michael Skynner sell?

He sold 824 shares on 10/02/2025 and 978 shares on 10/03/2025, totaling 1,802 shares.

Why were the BCYC shares sold by the insider?

The filing states the sales were mandatory "sell-to-cover" transactions to satisfy statutory tax withholding in connection with RSU vesting.

At what prices were the BCYC shares sold?

The weighted average prices reported are $8.40 for the 10/02/2025 sales and $8.41 for the 10/03/2025 sales; execution prices ranged from $8.31 to $8.50 across transactions.

How many BCYC shares does the insider own after these transactions?

Following the reported transactions the insider's direct beneficial ownership is 118,277 ordinary shares.

Were these transactions discretionary trades by the insider?

No. The filing specifies they were required by the award agreement to fund tax withholding and not discretionary sales.