Obama was elected Nov. 4, 2008.
The Dow plunged more than 400 points on each of the next two trading days.
The blue-chip average hit bottom at 6,547 in March 2009, less than two months after Obama took office.
Then it doubled over the next three-plus years as the crisis eased and a fragile economic recovery took root.
Things were looking so good that until recently, some analysts were betting on when the market might hit an all-time high.
Of course, the market today is far less precarious than it was in 2008. The financial system has stabilized. Europe appears to be serious about tackling its debt crisis, despite frequent setbacks.
The housing market appears to be coming back, and the economy has added jobs for more than two and a half years.
On the day after the 28 other presidential elections since 1900, the stock market has gone up 13 times and down 15 times, according to research by Bespoke Investment Group, a market research company.
The best day-after performance was in 1900, another re-election. The Dow jumped more than 3 percent on the day after William McKinley won a second term, according to Bespoke.
With the 2012 election over, traders turned to Europe's increasingly sickly economy, dragged down by a debt crisis for more than three years. The 27-country European Union said unemployment there could remain high for years.
The European Commission, the executive arm of the EU, said that it expects the region's economic output to shrink 0.3 percent this year. In the spring, the group predicted no change.
For next year, the commission predicted 0.4 percent growth, barely above recession territory. It predicted 1.3 percent last spring.
Renewed focus on European economic problems also pushed the price of oil down $4.27 per barrel, its biggest decline of the year, to finish at $84.44, the lowest since July 10.