Fortune ran the numbers as of the stock market close yesterday to measure market performance from Inauguration Day through Election Day for the first terms of both Trump and Obama. Trump’s tenure was certainly a good stretch for investors: The S&P 500 index rose 45.7% over that time, for an annualized return of 10.5% a year. 

But that still doesn’t come close to matching the gains seen under Barack Obama. During Obama’s first term, the S&P was up 77.4% for an annualized total return of 16.3%.

Obviously, the stock market that each President inherits has everything to do with underlying economic conditions, as well as sheer luck.

Fortune contributor Ben Carlson recently looked at economic conditions at the beginning of presidential terms going back to 1881 when Chester Arthur moved into the White House. As Carlson writes, “Looking at the starting and ending valuations can be instructive to understand how things changed during a President’s time in office. The Coolidge years took place during the Roaring Twenties, which saw stocks go from insanely low valuations to insanely high valuations just before the onset of the Great Depression. Clinton’s two terms saw markets go from above-average valuations to the highest valuations in history. George W. Bush was in office as those valuations were worked off while Obama timed the lows pretty closely for the start of the next bull market.”

Indeed, over Obama’s two terms, the S&P 500 would go on to rise 166%.

But whoever wins this year’s race “will inherit one of the most challenging market environments to start a presidential term in history,” writes Carlson. Valuations have exploded—so stocks will have the second-highest starting CAPE ratio ever for a President (The CAPE ratio is Robert Shiller’s well-regarded metric for valuing stocks). And, Carlson adds, the President will be dealing with “by far the lowest interest rates in the 140 or so year history of this data.”

That could give some clues as to why the stock market itself predicted a change in leadership. According to Fortune’s Jen Wieczner, if the market is down over the three months preceding an election, that’s a historically reliable signal that there will be a change of power. As of the market close on Friday, Oct. 30, the S&P 500 was down 0.6%. “Though the dip is minor, the negative S&P 500 performance over those three months indicates that the incumbent party—in other words, President Trump—will be voted out of the White House and replaced with a Democrat,” Wieczner wrote.

Additional reporting by Scott DeCarlo.