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

Reporting relationship: CEO and President, Director
Issuer ticker: CTAA
Reported as of: 25 Feb 2026
Net transaction value: $0
SEC form: 3
Accepted by SEC: 06 Mar 2026, 17:00:33 UTC
Source filing: View source filing
Reporting owner signature: /s/ William Brock

Key filing fact

William Brock filed Form 3 for Clearthink 1 Acquisition Corp. (CTAA) on 06 Mar 2026.

Key facts

This page summarizes William Brock's Form 3 filing for Clearthink 1 Acquisition Corp. (CTAA).
0 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 06 Mar 2026, 17:00.

Change

No earlier filing in this sequence is available for direct comparison.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Official SEC source

Ownership activity is grounded in SEC Form 3 disclosures.

View source filing

Reporting Owners (1)

CIK 0002114325 Primary reporting owner

Brock William

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

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

CTAA holding

Class A Ordinary Shares

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 315,000
Date: 25 Feb 2026
Ownership: By ClearThink 1 Sponsor LLC
Footnotes: F1, F2

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

CTAA holding Derivative

Class B Ordinary Shares

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 25 Feb 2026
Ownership: By ClearThink 1 Sponsor LLC
Underlying class: Class A Ordinary Shares
Underlying amount: 4,791,667
Exercise price
Footnotes: F2, F3, F4

CTAA holding Derivative

Rights

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after
Date: 25 Feb 2026
Ownership: By ClearThink 1 Sponsor LLC
Underlying class: Class A Ordinary Shares
Underlying amount: 63,000
Exercise price
Footnotes: F2, F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 5 footnotes

Footnote 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.

Footnote 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.

Footnote 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.

Footnote 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.

Footnote 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.