These funds are the first physically backed PGM ETFs listed in the US, which means the fund holds physical bullion in a vault as the assets of the fund.

Some analysts say the rise in prices for these commodities, and thus demand from investors, mirrors the already established European market.

"We have strong interest in Europe for our physically backed platinum and palladium ETFs over a number of years, with especially strong investment flows in 2009," says Nicholas Brooks, head of research and