Rare stock-market event? Here’s how many times the S&P 500 has seen a 9-day winning streak in the last 95 years.

In his “chart of the day,” Reid notes that going back to 1928, the S&P 500
SPX
and its precursors have seen 31 nine-day winning streaks, or one every 3.1 years. The chart below illustrates how the current 8-day run through Wednesday’s close would stack up on a historical basis.

The Nasdaq Composite
COMP
on Wednesday extended its winning streak to 10 days, the longest since an 11-day run from November 2021. The Dow Jones Industrial Average
DJIA
snapped a seven-day winning streak.

As the chart and data show, the S&P 500’s current run is hardly a regular event, but if bulls can extend the streak a few more days beyond Thursday they will indeed be in rarefied air.

Reid broke down the frequency of winning streaks, up to the record 14-day run that took place more than 50 years ago (the figures are cumulative, reflecting how many times the S&P 500 has passed these points):

• An 8-day winning streak has happened 63 times (average c. every 1.5 years)

• A 9-day streak has happened 31 times (average c. every 3.1 years)

• A 10-day streak has happened 15 times (average c. every 6.3 years)

• An 11-day streak has happened 8 times (average c. every 11.9 years)

• A 12-day streak has happened 5 times (average c. every 19 years)

• A 13-day streak has happened 1 time (average c. every 95 years)

• A 14-day streak has happened 1 time (average c. every 95 years)

“So the current run is something that happens around every 18 months on average. However for every day this run continues the rarity values roughly doubles until we get beyond day 12, a point where there’s only been one longer run, a 14-day winning streak in 1971,” he wrote.

In other words, if the market keeps going up next week, Reid said, “we could see an event rarer than Halley’s comet.”