[Form 4] BICYCLE THERAPEUTICS PLC Insider Trading Activity

Rhea-AI Filing Summary

Bicycle Therapeutics (BCYC) reported insider sales by Michael Charles Hannay, the company's Chief Product & Supply Chain Officer and a director. He recorded sales on 10/02/2025 and 10/03/2025 totaling 723 ordinary shares sold at weighted average prices near $8.40. The filing explains these were sell-to-cover transactions required to satisfy statutory tax-withholding on vested restricted stock units, not discretionary dispositions. After the transactions the reporting person owned 53,102 ordinary shares, indicating continued significant direct ownership.

Positive

• Sell-to-cover sales were mandatory under the award agreement, not discretionary
• Reporting person retains substantial ownership with 53,102 shares after transactions

Negative

• Total holdings decreased by 723 shares following the transactions

Insights

Corporate Governance Analyst

TL;DR: Mandatory "sell-to-cover" tax sales reduced holdings by 723 shares, leaving the officer with 53,102 shares.

The reported transactions on 10/02/2025 and 10/03/2025 are coded as sales to cover statutory tax obligations from vested restricted stock units. The filing states these sales were required by the award agreement and were executed in multiple trades at weighted average prices around $8.40.

This mechanism means the sales did not reflect a voluntary liquidation decision by the officer, which lessens governance concerns. Monitor future Form 4s for any discretionary sales or changes in beneficial ownership levels over the next 12 months.

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^*

Hannay Michael Charles Ferguson

(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 PROD & SUPPLY CHAIN OFF

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		473(1)	D	$8.4(2)	53,352	D
Ordinary Shares	10/03/2025		S		250(1)	D	$8.41(3)	53,102	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 $8.37 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 insider Michael Hannay sell (BCYC)?

He sold a total of 723 ordinary shares in two transactions on 10/02/2025 and 10/03/2025 at weighted average prices near $8.40.

Why were the BCYC shares sold by the officer?

The filing states the sales were sell-to-cover transactions required to satisfy statutory tax-withholding obligations on vested restricted stock units, per the award agreement.

How many BCYC shares does the reporting person own after the sale?

After the reported transactions the reporting person beneficially owned 53,102 ordinary shares.

Were the sales discretionary or required for taxes?

The sales were described as mandated by the award agreement to cover minimum statutory tax withholding and therefore were not discretionary.

At what prices were the BCYC shares sold?

The weighted average prices reported were approximately $8.40 (range $8.37–$8.45) and $8.41 (range $8.40–$8.50) across the transactions.