Mr. Erfan Kazemi reports

HORIZON COPPER ANNOUNCES FILING AND MAILING OF MEETING MATERIALS FOR THE SPECIAL MEETING OF SECURITYHOLDERS ON OCTOBER 9, 2025

Horizon Copper Corp. has filed its notice of meeting, management information circular and related documents with securities regulators in connection with the special meeting of the holders of common shares of the company and the holders of common share purchase warrants of the company. The meeting materials have also been mailed to securityholders and can also be accessed on the company's website and on Horizon's SEDAR+ profile.

Meeting details

The meeting is to be held on Oct. 9, 2025, at 8 a.m. Vancouver time, in the Copper boardroom at the company's head office located at Suite 3200, 733 Seymour St., Vancouver, B.C., Canada, V6B 0S6. Only securityholders of record as of the close of business on Sept. 8, 2025, the record date for the meeting, are entitled to receive notice of, attend and vote at the meeting.

At the meeting, securityholders will be asked to pass a special resolution approving an arrangement involving Horizon, Royal Gold Inc. and International Royalty Corp., a wholly owned Canadian subsidiary of Royal Gold (AcquireCo), whereby Royal Gold will indirectly through AcquireCo acquire all of the issued and outstanding Horizon shares (other than those held by Sandstorm Gold Ltd.) and through Horizon acquire all of the outstanding Horizon warrants. Shareholders will receive $2 for each Horizon share held, and warrantholders will receive $2 less the applicable exercise price, per underlying share, for the Horizon warrants held. The consideration implies an 85-per-cent premium to the 20-day volume-weighted average trading price of the Horizon shares on the TSX Venture Exchange for the period ended July 4, 2025, and a 72-per-cent premium to the closing price of the Horizon shares on the TSX Venture Exchange on July 4, 2025, being the last trading day before the announcement of the arrangement. When accounting for the Horizon shares and all other securities of the company, the all-cash transaction is valued at approximately $196-million (U.S.).

Board recommendation

The board of directors of Horizon (with the two directors having disclosable interests abstaining from voting), after receiving the unanimous recommendation of a special committee of independent directors of Horizon, unanimously determined that the arrangement is in the best interests of Horizon and unanimously recommends that securityholders vote for the arrangement resolution. The determinations and recommendations of the special committee and the board are based on various factors set forth below and as described more fully in the circular.

Strategic rationale

The Horizon transaction represents a compelling value for securityholders for the following reasons:

• Significant premium: The consideration represents a premium of 85 per cent to the 20-day volume-weighted average price of the company shares and of 72 per cent to the closing price of the company shares, on the TSX-V, as of July 4, 2025, the last trading day before the announcement of the arrangement.
• All-cash offer with no financing condition: The all-cash offer with no financing condition delivers certainty of value and immediate liquidity for securityholders.
• Compelling value relative to alternatives: The special committee and the board considered the company's stand-alone business strategy in light of Sandstorm's ownership in, and commercial agreements with, Horizon and in the context of current economic and market conditions, and concluded that the arrangement would provide greater and more certain value to securityholders than would reasonably be expected from the continued execution of the company's strategic plan.
• Daylights long-dated equity cash flows: The offer immediately crystallizes future value for securityholders while eliminating the effect of long-term business and execution risk, including due to financial markets and economic conditions.

Your vote is important. The board of directors of Horizon (with two directors having disclosable interests abstaining from voting) unanimously recommends that securityholders vote for the arrangement resolution. The deadline for voting Horizon shares and Horizon warrants by proxy is 8 a.m. Vancouver time on Oct. 7, 2025.

Questions and voting assistance

Securityholders who have questions about the meeting or require assistance in voting may contact the company's proxy solicitation agent.

Laurel Hill Advisory Group

North American toll-free:  1-877-452-7184

Outside of North America:  1-416-304-0211

By e-mail:  assistance@laurelhill.com

About Horizon Copper Corp.

Horizon Copper is a premier copper company holding a portfolio of unparalleled copper assets, including a 1.66-per-cent net profit interest on the Antamina copper mine, exposure to the Oyu Tolgoi copper mine through a 24-per-cent equity ownership in Entree Resources Ltd. and a 30-per-cent interest in the copper-gold Hod Maden project.

We seek Safe Harbor.