Quarterly Activities/Appendix 5B Cash Flow Report

• Major 1 million ounce gold resource defined at Side Well
• Spectacular high-grade gold intersected in deep drilling at Mulga Bill
• Aggressive exploration continues with 34,000m of drilling completed

The December quarter was the busiest three months in Great Boulder Resources' history, with more than 34,000m of drilling completed at the Side Well Gold Project. This intense period of drilling activity culminated in the announcement of a 1.02 million-ounce Mineral Resource Estimate in December, a major milestone for the company as it continues to discover new gold mineralisation while advancing the Side Well project towards development. Drilling during the quarter focused on resource definition at Eaglehawk and Golden Bracelet, as well as an ongoing regional AC drilling program and an EIS co-funded program of deep diamond holes beneath the Mulga Bill and Eaglehawk deposits. The deep diamond drilling at Mulga Bill intersected spectacular coarse gold, highlighting the potential for extremely high-grade gold mineralisation at depth. Moving into 2026, Great Boulder will continue its aggressive growth and development strategy at Side Well, with a strong pipeline of new and extensional gold targets. The company will also focus on advancing the Ironbark project towards mining approvals. At the end of December, Great Boulder had a cash balance of $12.0 million, which was supplemented by an additional $3.3 million from the exercise of options during January.

Great Boulder Resources has not provided any high-importance, price-sensitive forward-looking financial metrics in the announcement.

Great Boulder Resources will continue its aggressive growth and development strategy at the Side Well Gold Project, with a strong pipeline of new and extensional gold targets. The company will also focus on advancing the Ironbark project towards mining approvals.