Darius McDermott: How to invest in oil

Oil's been something of a trendy buy among more adventurous investors this year and while there's a lot of commentary about arguing for both the bull and bear case, it's been harder to find good advice on the best way to actually buy the stuff. If you've got some oil enthusiasts among your clients, who are asking the question, the answer is more complex than you might initially think. Earlier this year, I myself was one of those who wanted to 'take a punt'. The spot had fallen to below US$30 a barrel. I could only see it going up from there - at least over the long term - so I thought...