The Standard & Poor’s 500 index, the broadest measure of the stock market, is now officially in a “correction.”

That’s what Wall Street calls a decline of 10 percent of more from a stock index’s most recent peak, and something that hasn’t happened in almost two years, an unusually long gap.

The S&P 500 hit its most recent peak on Jan. 26. It fell 3.8 percent Thursday. That, plus losses going back to last week, wiped out its gains for this year and sent the index back down to levels last seen in November.

Not only are corrections common during bull markets, they’re seen as entirely normal and even healthy. They allow markets to remove speculative froth after a big run-up and allow investors to buy stocks at more reasonable prices.

Here are the past 12 corrections in the S&P 500 index:

Span of the correctionDecline in Percent

Jan. 26, 2018-Feb. 8, 2018 10.2

May 21, 2015-Feb. 11, 201614.2

April 29, 2011-Oct. 3, 201119.4

April 23, 2010-July 2, 201016

Nov. 27, 2002-March 11, 200314.7

July 16, 1999-Oct. 15, 199912.1

July 17, 1998-Aug. 31, 199819.3

Oct. 7, 1997-Oct. 27, 199710.8

Oct. 9, 1989-Jan. 20, 199010.2

Oct. 10, 1983-July 24, 198414.4

Feb. 13, 1980-March 27, 198017.1

Oct. 5, 1979-Nov. 7, 197910.2


Source: S&P Dow Jones Indices, FactSet