Shares in Australian Mines (AU:AUZ) leapt 150% to lead this week's market risers due to what it described as an arbitrage situation.

The company yesterday responded to a price and volume query from the ASX by pointing out that its market capitalisation was about 10% of a projected A$1.2 billion value for Clean TeQ Holding with its broadly similar cobalt-nickel-scandium project.

"The significant disparity between Australian Mines and Clean TeQ's market capitalisation appears to have created an arbitrage situation whereby investors can gain exposure to the cobalt-nickel market via Australian Mines at a material discount to its peers," the company said.

MD Benjamin Bell was in Hong Kong at an investor conference and the company said based on discussions with investors, the market cap disparity was attracting new investors.

Lepidico (AU:LPD) rose 100% in the wake of lithium miner Galaxy Resources (AU:GXY) investing $2.9 million to take a 12% stake in the junior.

The funding will expedite Lepidico's work to commercialise its L-Max metallurgical process that can produce lithium carbonate from lithium-rich mica minerals.

Meanwhile, third-placed nickel play Resource Mining Corp (AU:RMI) was at a loss to explain its sudden gains.

"RMI is unware [sic] of any explanation for the recent trading," the company told the ASX today.

The company has scaled back activity but maintained ownership of its Wowo Gap nickel project in Papua New Guinea and noted in its recent annual report that nickel market fundamentals were improving.

Finally, the gold price was lower today at $1,277 an ounce as the likelihood increases of a US rate rise in December.