Economist, Paul McCulley, actually coined the term "Minsky moment" in 1998.

The phrase "Minsky moment" has been popping up a lot in financial news reports about the turmoil roiling financial markets worldwide. It's named after Hyman Minsky (1919-1996), an economist known as a rather pessimistic contrarian during his lifetime for arguing that markets are inherently unstable and long stretches of good times just end in bigger collapses.

If you're not sure exactly what a Minsky moment is, the Wall Street Journal's Justin Lahart offered a wonderfully clear explanation:

At its core, the Minsky view was straightforward: When times are good, investors take on risk; the longer times stay good, the more risk they take on, until they've taken on too much. Eventually, they reach a point where the cash generated by their assets no longer is sufficient to pay off the mountains of debt they took on to acquire them. Losses on such speculative assets prompt lenders to call in their loans. "This is likely to lead to a collapse of asset values," Mr. Minsky wrote.

When investors are forced to sell even their less-speculative positions to make good on their loans, markets spiral lower and create a severe demand for cash [that can force central bankers to lend a hand]. At that point, the Minsky moment has arrived.