Last month, famed short seller Carson Block of Muddy Waters Research called the Chinese stock market the ultimate pump and dump.
Now, after that market has lost 24 percent of its value in just the last month, Block is warning Europe's markets could be the next shoe to drop.
"Europe is actually interesting from a short perspective. We've been spending a little bit of time looking there," said Block on CNBC's "Fast Money" last week.
Markets in Europe have been under pressure as Greece and the rest of the euro zone fight to come to an agreement over that nation's growing pile of debt. Greece is scrambling to get a last minute deal through, but would still have a long road ahead of it to a full recovery.
Now Block is setting his sights there for his next big short.
"We just kind of feel that investors and maybe regulators have been complacent there for some time. So from the perspective of the type of things we like to short, where there's some management wrongdoing or just pulling the wool over shareholders' eyes, Europe could be interesting in that regard," he said.
Yet the crisis-hit region is a tough nut to crack. European regulators, notoriously sensitive about short selling, recently slapped fines on several hedge funds for trying to profit from Greece's banking travails.
Block has previously warned against the dangers of investing in China, saying it is an unsafe place to invest, with many companies enjoying inflated market capitalizations.
Also, the analyst had the correct call on several Chinese companies, including NQ Mobile, which is down about 60 percent in the past two years; and Superb Summit, which has been under a trading halt after he made the call.
"Calling the top on a market, especially a bubble, is impossible," warned Block.