It was about 9 years ago that then-Federal Reserve chairman Alan Greenspan warned investors of "irrational exuberance." Then at issue was the run up of hi-tech stocks. The question is if we are experiencing a similar "irrational exuberance" with regard to the surge in crude oil prices.

I know the arguments that there is too much demand for the available supply, that oil is a finite resource and the world is running out of crude, and that very few new sources of crude have come online in decades. My question is, didn't the market know this 6 months ago? All of the sudden oil traders woke up one morning and realized that we had all these problems?

What I don't understand is that you can't have it both ways. You can't claim that the world has entered a sustained slow growth era, and yet continue to claim that strong demand is what is causing the surging price. If we do still see very strong demand than maybe the global economy isn't as bad as most think.

I am no technical analyst, but the way crude has been trading sure has the makings of a bubble ready to pop. It's one thing to slowly and steadily increase in price, like we have seen for the last 5-6 years. It's quite another to see it move straight up in a vertical line, like we have seen of late.

Investors beware. This sure seems like another example of "irrational exuberance."

Aaron Katsman is the lead Portfolio Manager and Managing Director of America Israel Investment Associates, LLC. and Senior Editor of IsraelNewsletter.com. DISCLOSURE: Writer's fund has no position in any stock mentioned, as of 6/29/08.