Jim Rogers is one of the biggest names in commodity investors. A long-time partner of George Soros, Rogers emerged in the late-1990s as the biggest bull in the commodities game, going so far as to pen a book called Hot Commodities predicting a 15-20-year boom in commodity prices.

Somewhat less well known is the fact that Rogers is also the founder of a great commodity index, the Rogers International Commodity Index, which is famous for being the most diverse of all commodity indexes—it includes not just oil and gold, but things like adzuki beans and rice. A full list of the commodity holding of the broad-market fund, and the subindexes, is included in the table below.

Interestingly, that diversification has boosted historical returns: the RICI index has outperformed the DJ-AIG Commodity Index handily over the past five years, delivering 21.63% compound returns against 15.19% for the better-known DJ-AIG.

Until recently, investors had no easy way to tap in to the index. There was a high-priced mutual fund and a low-volume TRAKR, but there was no low-cost and liquid way to access the index, the way there was for indexes like the Dow Jones AIG and the GSCI.

All that changed on October 18, however, when the ELEMENTS consortium quietly launched four ETNs tied to the Roger index (RJI) and three subindexes: Agriculture (RJA), Energy (RJN) and Metals (RJZ).

ETNs are debt-linked products that trade like ETFs. They have marked advantages over ETFs, such as having zero tracking error and having (by most accounts) very favorable tax treatment. However, they do come with credit risk: If the underwriting bank defaults, investors are out of luck.

The Rogers commodity ETNs are backed by the Swedish Export Corp, a quasi-governmental bank from Sweden with an Aa1/AA+ credit rating.

The RJI prospectus is available here.