You can read about it at
Financial meltdown: Hyman Minsky warned us this would happen
Here is a key exerpt:
"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. At that point, the Minsky moment has arrived."
According to one expert:
""We are in the midst of a Minsky moment, bordering on a Minsky meltdown," says Paul McCulley, an economist and fund manager at Pacific Investment Management Co., the world's largest bond-fund manager, in an email exchange."
I don't think that the economics profession has taken much interest in this over the years. The book Modern Macroeconomics: Its Origins, Development And Current State does not even mention his name. An earlier edition of the book from 1995 did list three of Minsky's works in the bibliography. But apparently the authors no longer thought he was worth mentioning.
One more thing, I had a post last year about another theory on why we see such great volatility in the market. It reminds me of Minksy's theories. The post was Interesting Theory on Stock Market Fluctuations. Here is the post:
"Nicholas Barberis of the University of Chicago Business School has an interesting article called Search for the Holy Grail: Demystifying the Stock Market. This is clearly written for a general audience. The basic idea seems to be that when the market is up, people feel like they are good investors and that they are playing with the "house's money." So they will keep buying, making the market go up even more. But when things are down, people get pessimistic and want to sell (also because of "loss aversion," the idea that people have a bigger drop in utility from losing a dollar than the gain from finding a dollar). So people sell more quickly since they don't want to lose anything. Then the market goes down even more. So the ups and downs are bigger than you might expect."