William Brock - 25 Feb 2026 Form 3 Insider Report for Clearthink 1 Acquisition Corp. (CTAA)

Role: CEO and President, Director
Signature: /s/ William Brock
Issuer symbol: CTAA
Transactions as of: 25 Feb 2026
Net transactions value: $0
Form type: 3
Filing time: 06 Mar 2026, 17:00:33 UTC
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Brock William	CEO and President, Director	C/O CLEARTHINK 1 ACQUISITION CORP., 150 E. PALMETTO PARK ROAD, SUITE 202, BOCA RATON,	/s/ William Brock	06 Mar 2026	0002114325

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
holding	CTAA	Class A Ordinary Shares						315,000	25 Feb 2026	By ClearThink 1 Sponsor LLC	F1, F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	CTAA	Class B Ordinary Shares							25 Feb 2026	Class A Ordinary Shares	4,791,667		By ClearThink 1 Sponsor LLC	F2, F3, F4
holding	CTAA	Rights							25 Feb 2026	Class A Ordinary Shares	63,000		By ClearThink 1 Sponsor LLC	F2, F5

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents Class A ordinary shares underlying the private placement units (the "Private Units") purchased concurrently with the initial public offering of the Issuer. The number of Class A ordinary shares does not include the rights entitling the holder to receive one-fifth of one Class A ordinary share upon the consummation of a business combination, which comprise a part of the Private Units of the Issuer purchased by ClearThink 1 Sponsor LLC (the "Sponsor") concurrently with the consummation of the Issuer's initial public offering.
F2	The Sponsor is the record holder of the shares reported herein. ClearThink 1 Sponsor Manager LLC, the managers of which are the Reporting Person, the Issuer's Chief Executive Officer, and Ari Brown, a Managing Director at ClearThink Capital LLC, is the sole managing members of the Sponsor. Mr. Brock and Mr. Brown have sole voting and investment discretion with respect to the ordinary shares held of record by the Sponsor.
F3	As described in the Issuer's Registration Statement on Form S-1, as amended (File No. 333-292967) under the heading "Description of Securities - Ordinary Shares", the Class B Ordinary Shares will automatically convert into Class A ordinary shares at the time of the Issuer's initial business combination or earlier at the option if the holder on a one-for-one basis, subject to certain adjustments described therein and have no expiration date.
F4	Includes up to 625,000 founder shares that will be forfeited depending on the extent to which the underwriters' over-allotment option is exercised.
F5	Represents 315,000 rights underlying the Private Units. Each right entitles the holder to receive one-fifth of one Class A ordinary share upon the consummation of the Issuer's initial business combination.