Bradda Head Lithium rallied 8% as the company said recent drilling on its lithium clay assets in Arizona pointed to a significant resource upgrade when all of the data is totted up.
Holes drilled in the Basin East Extension showed the clays from which lithium is extracted thickened to the west, northwest and north and most likely extend into other Bradda claims in the area, it said.
Drilling at another Arizona prospect, San Domingo, is set to get underway to delineate another resource in the region.
Shares rose 0.3p to 4.1p.