Columnist and money manager Doug Kass says that while more and more investors seem to be jumping on the bullish train, he’s getting more bearish.

“Despite nearly no one willing to fight the very strong tape, I am growing increasingly cautious on fundamental grounds and on technical (and “feel”) grounds,” Kass writes on TheStreet.com. “Color me more bearish as I feel more willing to expand my short exposure — and I am putting my portfolio where my words and analysis are.”

In a separate piece, Kass discusses the fundamental reasons for his bearishness. Among them: He says current assessments of the economy are too optimistic, and he says rising food and gasoline prices and a declining dollar are bringing us toward several “economic tipping points”. In the first article, Kass also says he doesn’t buy the “near-universal chorus of optimism” that Osama bin Laden’s death will mean a big boost in confidence.

Still, Kass says that while he is net short, he’s not “over-the-skies short … yet”. He says he’s “trying to ‘time’ the short opportunity (as best I can!) with the knowledge that the bullish trend still may remain intact.”