The has logged losses eight sessions through Thursday, in only the second time it's done so in the past two decades.
The last time the large-cap index fell in eight consecutive sessions was in October 2008, when the market dropped massively during the first 10 calendar days of that month, in a market crash that came soon after the Lehman Brothers bankruptcy.
Of course, the recent market move hardly resembles 2008's. While the market was 23 percent lower after those eight sessions in 2008, the S&P has fallen by less than 3 percent during the current losing streak.
Still, this isn't something we see often. Before 2008, such a string of losses was last observed in June 1996; before that, in September 1991; and before that, in August 1982.
The recent string of slides reflects the "uneasy limbo" in which the market finds itself, according to Michael Block, chief strategist at Rhino Trading Partners.
"There's a lot of doom and gloom regarding political uncertainty, regarding the Fed and regarding the overhang of Brexit," Block told CNBC in a Thursday phone interview. "Active managers are finding little motivation to stick their necks out here," leading to a lack of willing buyers in the market.
Indeed, between oil falling and bond yields rising, the macro market isn't giving bulls much to work with. And the perception that Republican Donald Trump's chances of winning the presidential election are rising creates a major source of uncertainty for investors.
Indeed, many are viewing the risks as skewed to the downside — according to Nicholas Colas of Convergex, the S&P would likely rise 2 to 3 percent should Democrat Hillary Clinton win but fall 10 to 15 percent on a Trump victory.
The recent decline "has been orderly, it's been on low volume and it's been — dare I say — complacent," Block said.
But while this might not feel anything like 2008, the tremendous amount of uncertainty could well mean the string of mild losses will continue.
If the S&P closes lower once again on Friday, that will be the longest string of losses since 1980.
