The old lore about the best way to cure a hangover is with a few more nips of whatever it was you were imbibing the previous evening, commonly known as "hair of the dog."
The extension of this rally in stocks and just about every other asset identified with risk feels like a hair-of-the-dog situation. Between 2003 and mid-2008, easy flow of capital facilitated revelry in stocks, emerging markets, real estate, bonds, and high-yielding currencies.
When investors invariably lost interest in an asset class where valuations could no longer be denied, they flocked to another - witness $150-a-barrel oil, $1,000 gold prices, and crazy gyrations in wheat and soybeans, of all things.
Then the hangover came. Major stock indexes were cut in half. Oil went to $30 a barrel, and investors fled for cover in the dollar and the safety of Treasury bonds.
With U.S. Federal Reserve and other central banks cutting rates to nothing, money worked its way back into the markets, though.