Warren Buffett's Berkshire Hathaway (BRK.A) has holdings that span many industries, like health care, consumer goods, energy, insurance, real estate, rail and so on. Because of this, he has a good perspective on economic sentiment. And, according to a recent speech at the Montana Economic Development Summit, Buffett is unabashedly bullish on things.

First of all, he thinks a double-dip recession is highly unlikely. Then again, it appears that many investors believe the same. But, the question is: Can the U.S. economy show more robust growth?

He was two years early and now he might be two years late. His facts were right. His timing was off, and I think if you wait for the illustrious NYU professor Nouriel Roubini to give the "all clear sign" you will miss even more of the market upside than you have missed already.

On February 18 of this year I wrote Buffett says buy, then sells, Roubini says wait -- what's an investor to do? -- and it will make interesting reading today. After all it was about three weeks before the market really hit bottom, and I called that, too, posting on March 9: Nostradamus was a punk! Have we reached bottom? -- a lucky call for sure. However, the number of folks thinking the world was coming to an end seemed like the ultimate capitulation.