Waiting for the Fed

"This is the most speculative momentum-driven equity market since the early 1930s," Gluskin Sheff economist David Rosenberg wrote in a note to clients Monday.

Of course, stocks have rallied in part because investors perceive the worst-case scenario -- a 1930s-style Depression -- is off the table. And while the gains have been remarkable, they come after an even bigger decline. The S&P is still down 16% since Lehman Brothers collapsed in September.

But while most people take the rise in stocks as a hopeful sign for the economy, some see evidence that the Fed has been financing a speculative mania that could end in another damaging rout.

Recent weeks have brought huge rallies in some of the lowest-quality stocks -- including firms such as AIG, Fannie Mae and Freddie Mac that are being propped up by the government and are unlikely to return to health any time soon.

What's more, this year has brought an 80% surge in emerging market stocks, while the dollar has posted a 10% decline since March. A declining dollar and surging emerging markets were the hallmarks of the credit-fueled bull run earlier this decade.