Launches in the indexed product universe are becoming increasingly esoteric, as providers jostle for business. And Deutsche Bank is jostling harder than most through an exchange-traded commodity fund that will track – and potentially influence – the price of rhodium, one of the world's rarest metals.

The move follows Deutsche ETC launches for palladium, platinum, silver and gold. Palladium and platinum are also quite scarce. All five of the funds are grouped under a Ucits umbrella, which allows investors to pick and mix.