The S&P 500 briefly dipped into bear market territory: Here's what that means

The S&P 500 finished the day at 2,741, down about 5% for the session and about 19% below the all-time high it closed at on February 19.

The tech heavy Nasdaq is also 19% below its all-time high. Two other key market indexes, the Dow Jones Transportation Average and the small-cap focused Russell 2000, are already in a bear market.

The S&P 500 was last in a bear market in late 2007, 2008 and early 2009 -- during the height of the Great Recession and Global Financial Crisis. The index fell more than 56% from its peak before bottoming out.

Stocks have soared since then, with the S&P 500 more than quadrupling from its March 2009 low, a gain of over 300%.

The blue chip index is now only 33 points away from joining the Dow in bear status, given the recent bloodbath on Wall Street. It's uncertain how long this market downturn will last -- and how severe it will be.

In the last bear market before 2008, the burst of the tech stock crash/dotcom bubble of 2000-2002, the S&P 500 lost nearly half its value.

Still, not all bear markets last that long or have stocks plunge quite as much. That was the case in the early 1980s, when stocks fell a far more modest (by today's standards) 27% between 1980 and 1982 due to sky-high inflation and rising interest rates. The Black Monday bear market of 1987 lasted only a few months.

There are hopes that the coronavirus outbreak will lead to only a temporary pullback in earnings and economic growth and that sales, profits and GDP will rebound by the end of the year. But it's still too soon to say.

It's also worth noting that a bear market does not have to necessarily lead to -- or happen during -- a recession. It's the job of the National Bureau of Economic Research to determine when the economy is in recession -- not the stock market, and certainly not stock market prognosticators.