"I would just like to say a very belated thank you to Eoin for his very helpful reply to my e-mail about the Crude Oil ETF on 23rd July and in particular the reference to the article by Peter Robinson et al. I suppose the lesson I have learned from this is that one should always keep a chart of the index you hope the ETF is following superimposed on the ETF price, particularly when the commodity it is tracking is something which is difficult to store. "

Eoin Treacy's view Thank you for your kind words and you are welcome. I think monitoring an overlay chart of the fund and commodity that it is supposedly tracking is an excellent idea. Let me demonstrate how this can be achieved using the Chart Library, taking NYME Crude Oil and the ETFS Crude Oil Fund as examples.

It doesn't matter which one of the instruments you select first, but I will start with the NYME Crude Oil price which can be found using the Chart Library's dedicated search engine. Once you have selected the chart, you will need to add the second instrument as an overlay.

To do this, click on the Charting tab, found in the charcoal bar above the chart area. A popup window will appear and you will need to select the additional instrument from the Relative dropdown menu of popular options.

If the instrument you are looking for is not on the menu, as is the case with the ETFS Crude Oil Fund you will need to click on the 'Other Relative' tab highlighted in green and found directly underneath the Relative dropdown menu. Another popup window will appear and you can type "ETFS Crude" into the search field. The ETFS Crude Oil fund will be the top result. Click on it. Next go the smaller dropdown menu next to the Relative dropdown and select 'overlay' from that menu. Finally, hit Apply.