Full membership at the Chicago Board of Trade (CBOT) has hit its highest price for a year. A seat bearing the right to trade any contract at the second-largest US futures market sold for $475,000 (€392,800) late last month, almost $200,000 more than a sale this time last year.

The sharp rise comes on the back of strong growth in trading volumes, and a series of efforts by the CBOT to see off a threat from Eurex, the Swiss-German exchange, which plans to start its own US futures market next year.