Hedge fund titan John Paulson is predicting that Greece may default by the end of next month causing the euro to break up, according to Bloomberg News.

The billionaire hedge fund manager, who famously bet against the subprime mortgage market, thinks things will get really ugly if it does.

From Bloomberg News:

"We believe a Greek payment default could be a greater shock to the system than Lehman's failure, immediately causing global economies to contract and markets to decline,” the hedge fund said in the letter, a copy of which was obtained by Bloomberg News. The euro is "structurally flawed and will likely eventually unravel," it said.