Hello Crazy Gang,

You may have noticed that on many days the top share in the winner's board on Sharecrazy.com is an oil company.

Not the big oil companies like Shell (LSE: RDSB.L - news) or BP (LSE: BP.L - news) , you understand, but a small oily. This is a sure sign of how good the right choice of a small oil company can be.

However, there are quite often a few oil tiddlers towards the top of the loser's board each day. Though you're much more likely to find an oil company at the peak of the day's winners, than you will find a small oily at the top of the loser's board.

This is because oil companies rocket when they strike it rich or when some other company invests heavily in its chances of finding black gold.

Both these eventualities are enough to send an oil share up 100% in a day. And sometimes even more. Yes, gang, it's not all that uncommon for a modest oil set-up to improve very rapidly indeed.

And yet oil companies which are failing do so in more dignified a way. Their falls are not all that rapid as a rule, more like a nice steady, gentle decay.

But there's a problem here. If an oil company tumbles very slowly, as they tend to, then we can fail to see the demise at all. We look one day and one of our oil shares has lost 75% of its value. And we didn't even notice the weakness.

However, with oil companies this can be an advantage. For example, I lost a load of money (on paper) on Desire Petroleum (LSE: GB0002689494.L - news) and EEL. I didn't notice how badly they'd fared over the months. (I should have done, but that's another story).

So I did not sell - and being oil companies, they suddenly came back very strongly indeed - putting me well in profit. So there we - yet more proof that, in Crazyland, behind most black clouds, there's a blazing sun. Rock on.