If one particular commodity is being traded on more than one international exchange, the most liquid contract globally, in terms of volume and open interest combined, is then selected for inclusion in the index.
The sub-indices' contribution to main index from the beginning are Agriculture - 34.90%, Energy - 44.00%, Metals - 21.10% according to the RICI Handbook (see reference below).
When one invests in the RICI, one knows what one will own a few years down the road in sharp contrast to the other commodity indexes which change significantly.
[citation needed] For each commodity, the most valid (most actively traded from the committee point of view) expiration is chosen to be included into the RICI calculation.
[citation needed] The RICI's website (http://www.rogersrawmaterials.com/ Archived 2009-04-10 at the Wayback Machine) is not working from June 02, 2021.