X0202 SCHEDULE 13G 0001009268 XXXXXXXX LIVE Class A ordinary shares, par value $0.0001 per share 03/31/2026 0002040381 Pioneer Acquisition I Corp G7117W107 131 Concord Street Brooklyn, NY 11201 Rule 13d-1(d) D. E. Shaw & Co., L.P. DE 0.00 1252350.00 0.00 1252350.00 1252350.00 N 5.7 IA PN D. E. Shaw & Co., L.L.C. DE 0.00 1252350.00 0.00 1252350.00 1252350.00 N 5.7 OO D. E. Shaw Valence Portfolios, L.L.C. DE 0.00 1252350.00 0.00 1252350.00 1252350.00 N 5.7 OO David E. Shaw X1 0.00 1252350.00 0.00 1252350.00 1252350.00 N 5.7 IN Pioneer Acquisition I Corp 131 Concord Street, Brooklyn, NY 11201 D. E. Shaw & Co., L.P. D. E. Shaw & Co., L.L.C. D. E. Shaw Valence Portfolios, L.L.C. David E. Shaw The business address for each reporting person is: Two Manhattan West 375 Ninth Avenue, 52nd Floor New York, NY 10001 D. E. Shaw & Co., L.P. is a limited partnership organized under the laws of the state of Delaware. D. E. Shaw & Co., L.L.C. is a limited liability company organized under the laws of the state of Delaware. D. E. Shaw Valence Portfolios, L.L.C. is a limited liability company organized under the laws of the state of Delaware. David E. Shaw is a citizen of the United States of America. Y D. E. Shaw & Co., L.P.: 1,252,350 shares This is composed of 1,252,350 shares in the name of D. E. Shaw Valence Portfolios, L.L.C. D. E. Shaw & Co., L.L.C.: 1,252,350 shares This is composed of 1,252,350 shares in the name of D. E. Shaw Valence Portfolios, L.L.C. D. E. Shaw Valence Portfolios, L.L.C.: 1,252,350 shares David E. Shaw: 1,252,350 shares This is composed of 1,252,350 shares in the name of D. E. Shaw Valence Portfolios, L.L.C. David E. Shaw does not own any shares directly. By virtue of David E. Shaw's position as President and sole shareholder of D. E. Shaw & Co., Inc., which is the general partner of D. E. Shaw & Co., L.P., which in turn is the investment adviser of D. E. Shaw Valence Portfolios, L.L.C., and by virtue of David E. Shaw's position as President and sole shareholder of D. E. Shaw & Co. II, Inc., which is the managing member of D. E. Shaw & Co., L.L.C., which in turn is the manager of D. E. Shaw Valence Portfolios, L.L.C., David E. Shaw may be deemed to have the shared power to vote or direct the vote of, and the shared power to dispose or direct the disposition of, the 1,252,350 shares as described above constituting 5.7% of the outstanding shares, and, therefore, David E. Shaw may be deemed to be the beneficial owner of such shares. David E. Shaw disclaims beneficial ownership of such 1,252,350 shares. D. E. Shaw & Co., L.P.: 5.7% D. E. Shaw & Co., L.L.C.: 5.7% D. E. Shaw Valence Portfolios, L.L.C.: 5.7% David E. Shaw: 5.7% D. E. Shaw & Co., L.P.: 0 shares D. E. Shaw & Co., L.L.C.: 0 shares D. E. Shaw Valence Portfolios, L.L.C.: 0 shares David E. Shaw: 0 shares D. E. Shaw & Co., L.P.: 1,252,350 shares D. E. Shaw & Co., L.L.C.: 1,252,350 shares D. E. Shaw Valence Portfolios, L.L.C.: 1,252,350 shares David E. Shaw: 1,252,350 shares D. E. Shaw & Co., L.P.: 0 shares D. E. Shaw & Co., L.L.C.: 0 shares D. E. Shaw Valence Portfolios, L.L.C.: 0 shares David E. Shaw: 0 shares D. E. Shaw & Co., L.P.: 1,252,350 shares D. E. Shaw & Co., L.L.C.: 1,252,350 shares D. E. Shaw Valence Portfolios, L.L.C.: 1,252,350 shares David E. Shaw: 1,252,350 shares Y Y Y Y Y Y Exhibit 3: Joint Filing Agreement, by and among the Reporting Persons, dated May 15, 2026. D. E. Shaw & Co., L.P. /s/ Daniel R. Marcus 05/15/2026 D. E. Shaw & Co., L.L.C. /s/ Daniel R. Marcus 05/15/2026 D. E. Shaw Valence Portfolios, L.L.C. /s/ Daniel R. Marcus 05/15/2026 David E. Shaw /s/ Daniel R. Marcus 05/15/2026 Exhibit 1: Power of Attorney, granted by David E. Shaw relating to D. E. Shaw & Co., Inc., in favor of the signatories hereto, among others, dated August 1, 2024. Exhibit 2: Power of Attorney, granted by David E. Shaw relating to D. E. Shaw & Co. II, Inc., in favor of the signatories hereto, among others, dated August 1, 2024.