Company: HYAC-WT
Filing Date: 2025-10-10
Form Type: 425
Source: 0001104659-25-098547
Chunk: 1

Company: Haymaker Acquisition Corp. 4
Filing Date: 2025-10-10
Form: 425
Chunk 1
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 HYAC      |     | The New York Stock Exchange |
| Warrants, each whole warrant exercisable for one Class A ordinary share at an exercise price of $11.50 per share |     | HYAC WS   |     | The New York Stock Exchange |

Indicate by check mark whether the registrant is an emerging growth
company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange
Act of 1934 (§240.12b-2 of this chapter).

Emerging growth companyx

If an emerging growth company, indicate by check mark if the registrant
has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant
to Section 13(a) of the Exchange Act. ¨

| Item 1.01 | Entry into a Material Definitive Agreement. |

On October 9, 2025, Haymaker Acquisition Corp.
4, a Cayman Islands exempted company (“Haymaker” or “SPAC”), Suncrete, Inc., a Delaware corporation and direct
wholly owned subsidiary of SPAC (“New Suncrete” or “PubCo”), Haymaker Merger Sub I, Inc., a Delaware corporation
and a direct wholly owned subsidiary of PubCo (“Merger Sub I”), Haymaker Merger Sub II, LLC, a Delaware limited liability
company and direct wholly owned subsidiary of PubCo (“Merger Sub II” and together with Merger Sub I, the “Merger Subs”),
and Concrete Partners Holding, LLC, a Delaware limited liability company (“Suncrete”), entered into a Business Combination
Agreement, dated as of October 9, 2025 (the “Business Combination Agreement”).

Pursuant to the Business Combination Agreement,
and subject to the terms and conditions contained therein, the Business Combination will be effected in three steps: (a) SPAC will change
its jurisdiction of incorporation from the Cayman Islands to the State of Delaware (the “Domestication” and the time at which
the Domestication becomes effective, the “Domestication Effective Time”), (b) immediately following the Domestication Effective
Time, Merger Sub I will merge with and into SPAC (the “Initial Merger”), with SPAC surviving the Initial Merger as a wholly
owned subsidiary of PubCo (the time at which the Initial Merger becomes effective, the “Initial Mer