"Just a quick query about charts which I am sure has a very simple answer. When I compare the chart links you provided in the daily e-mail on 4th June for Cocoa and Cotton with their ETF equivalents (COCO and COTN), I notice a significant difference in chart appearance thus representing a significant difference in performance of investment vehicle.

"Is this simply the difference between investing through futures (presumably using spread betting) and investing through ETFs which I can only assume follow the daily price?

"Many thanks for the excellent and wise words that you convey in your Daily Comments - much appreciated for a novice investor like myself."

Eoin Treacy's view Thank you for this question which I'm sure will be of interest to other subscribers. Investment vehicles focused on tracking the performance of commodities generally track an index rather than the price of the future. The ETFS you mention are pegged to the Dow Jones UBS Total Return Indices whose price includes fund, contango and roll costs that one might not find in stock market tracking instruments. When a commodity such as US Cocoa trades in a large contango, as is currently the case, this is reflected in the price of the tracker, which will throw off its ability to track the on-the-run futures price. This means that doing one's due diligence is even more important with funds that deal in futures.