Stock Relapse imminent

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 (AIG, Fortune 500), Fannie Mae (FNM, Fortune 500) and Freddie Mac (FRE, Fortune 500) 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.

"We have put the band back together on a lot of this," said Howard Simons, a strategist at Bianco Research in Chicago. "That couldn't have happened without liquidity."

Though liquidity is admittedly a nebulous concept, there's no question that central bankers around the globe have poured huge amounts of money into the markets to ease the financial crisis. Given free money, investors' appetite for risk shoots higher and they gobble up stocks.

That's good, except when the outlook for economic growth doesn't seem to support the higher stock values.

"Many observers are wondering whether the strong stock market rebound since mid-March is already a forerunner of the next recovery or simply driven by a reflux of liquidity into riskier asset markets," Deutsche Bank Research analyst Sebastian Becker wrote in a report last month.