Dow futures plummeted by more than 800 points as Trump's path to victory looked increasingly likely.
Why did this happen?
Many economic predictions for the United States under a Trump presidency have been grim, and one advisory firm told Yahoo Finance that his win could cause the S&P 500's market value to drop by 7% — tantamount to over a $1 trillion loss of wealth.
An open letter in the Wall Street Journal published Nov. 1 — signed by 370 economists, eight of whom are Nobel laureates — warned that a Trump economic plan could have devastating consequences, describing him as "a dangerous, destructive choice for the country."
While markets and economists alike have shown extreme bearishness about a Trump presidency, there is a possible silver lining: Unexpected "black swan" events like Brexit frequently reveal markets' tendencies to overreact.
In fact, some financial experts suggest that a market overreaction on Nov. 9 — assuming stocks take a huge dive — could represent a buying opportunity if you have extra money to invest (aka, money you do not need to pay off debts or keep in your emergency fund).
"If someone has excess cash sitting on the sidelines that they had wanted to put to work in the markets all along," New York-based certified financial planner Roger Ma said in an email to Mic, "then tomorrow could be an opportunity to take advantage of stocks being 'on sale.'"
Unfortunately, taking advantage would probably require buying stocks in a brokerage account, because deposits into your 401(k) are slower. Making a payroll deduction change for an increased 401(k) contribution takes some time, Ma said: often one or two pay periods.
"By the time the change takes effect, the markets may have already recovered to pre-election levels," he cautioned.
Personal investment opportunities aside, a Trump presidency means many things for many Americans' money.
And then there's the question of how the next president will manage the U.S. health care and student debt crises.
On these fronts, it's less clear how much any reaction can be characterized as an overreaction.
Nov. 9, 2016, 2:53 a.m. Eastern: This story has been updated.