On today's Halftime Report, the O'Shares Chairman says now is the buying opportunity of a lifetime in Europe.

So what makes Europe a "screaming buy"?

O'Leary is a longtime buyer of European stocks and believes the heightened volatility is creating a great opening for investors.

"Ever so slightly over the past six months, my value screens keep showing me that European large-cap dividend paying stocks are significant better buys than their U.S. counterparts," he said.

While the million dollar investor is long European stocks, he's not a buyer of any European banks.

"Those things are so over regulated with absolutely no way to make money, with these margins crushed by zero and negative interest rates. It's way too early," said O'Leary.

So what names does he like? O'Leary is betting on companies like Roche, Novartis, Nestle, and GlaxoSmithKline.