BTC Development Corp. – Material Contracts Watch

from 8-K 3 pages BTC Development Corp. 2929 Arch Street, Suite 1703 Philadelphia, Pa 19104 September 29, 2025

from 8-K 11 pages Placement Unit Subscription Agreement

from 8-K 11 pages Placement Unit Subscription Agreement

from 8-K 10 pages Placement Unit Subscription Agreement

from 8-K 19 pages Registration Rights Agreement

from 8-K 16 pages Investment Management Trust Agreement

from 8-K 9 pages This Letter (This “Letter Agreement”) Is Being Delivered to You in Accordance With the Underwriting Agreement (The “Underwriting Agreement”) Entered Into or Proposed to Be Entered Into by and Among BTC Development Corp., a Cayman Islands Exempted Company (The “Company”), and Cohen & Co. Capital Markets (“Cohen”) and Keefe, Bruyette & Woods, Inc. (“Kbw” And, Together With Cohen, the “Underwriters”), Relating to an Underwritten Initial Public Offering (The “Public Offering”), of 25,300,000 of the Company’s Units (“Units”) (Including Up to 3,300,000 Units That May Be Purchased to Cover Over-Allotments, if Any), Each Comprised of One Class a Ordinary Share of the Company, Par Value $0.0001 Per Share (Each, an “Ordinary Share”), and One-Fourth of One Redeemable Warrant (Each Whole Warrant, a “Warrant”). Each Warrant Entitles the Holder Thereof to Purchase One Ordinary Share at a Price of $11.50 Per Share, Subject to Adjustment. the Units Shall Be Sold in the Public Offering Pursuant to a Registration Statement on Form S-1 and a Prospectus (The “Prospectus”) Filed by the Company With the Securities and Exchange Commission (The “Commission”). Certain Capitalized Terms Used Herein Are Defined in Paragraph 11 Hereof

from S-1/A 17 pages Investment Management Trust Agreement

from S-1 3 pages BTC Development Corp. 2929 Arch Street, Suite 1703 Philadelphia, Pa 19104 [---], 2025

from S-1 21 pages Form of Indemnity Agreement

from S-1 11 pages Placement Unit Subscription Agreement

from S-1 11 pages Placement Unit Subscription Agreement

from S-1 10 pages Placement Unit Subscription Agreement

from S-1 7 pages BTC Development Corp. 2929 Arch Street, Suite 1703 Philadelphia, Pa 19104 August 11, 2025

from S-1 18 pages Registration Rights Agreement

from S-1 17 pages Investment Management Trust Agreement

from S-1 9 pages This Letter (This “Letter Agreement”) Is Being Delivered to You in Accordance With the Underwriting Agreement (The “Underwriting Agreement”) Entered Into or Proposed to Be Entered Into by and Among BTC Development Corp., a Cayman Islands Exempted Company (The “Company”), and Cohen & Co. Capital Markets (“Cohen”) and Keefe, Bruyette & Woods, Inc. (“Kbw” And, Together With Cohen, the “Underwriters”), Relating to an Underwritten Initial Public Offering (The “Public Offering”), of 25,300,000 of the Company’s Units (“Units”) (Including Up to 3,300,000 Units That May Be Purchased to Cover Over-Allotments, if Any), Each Comprised of One Class a Ordinary Share of the Company, Par Value $0.0001 Per Share (Each, an “Ordinary Share”), and One-Fourth of One Redeemable Warrant (Each Whole Warrant, a “Warrant”). Each Warrant Entitles the Holder Thereof to Purchase One Ordinary Share at a Price of $11.50 Per Share, Subject to Adjustment. the Units Shall Be Sold in the Public Offering Pursuant to a Registration Statement on Form S-1 and a Prospectus (The “Prospectus”) Filed by the Company With the Securities and Exchange Commission (The “Commission”). Certain Capitalized Terms Used Herein Are Defined in Paragraph 11 Hereof

from S-1 3 pages Promissory Note