By Nico Grant October 8, 2016

“Companies will come. They will build. They will expand,” Donald Trump said at the first presidential debate. “It’s going to be a beautiful thing to watch.”

At the debate, Trump promised to lower corporate tax rates from 35 percent to 15 percent and bring back millions of jobs. And while Trump courted business, his rival, Hillary Clinton, reminded the audience that not a single Fortune 500 CEO supported his candidacy.

Trump claims to be the business-friendly presidential candidate, but investors disagree. They’re breathing a sigh of relief as the specter of a Trump presidency has started to fade. Trump collapsed in the first debate and stumbled since, dragging down his poll numbers. Investors responded by snapping up futures and Mexican pesos in jubilation.

“Talk of nationalism and populism is the greatest threat to the world,” said Mark Yusko, CEO and CIO at Morgan Creek Capital Management. “Trump really does personify uncertainty.”

Trump was nearly incomprehensible as he flailed on myriad policy topics in the final hour of the debate.

As he faltered, investors pounced.

S&P 500 futures spiked, up 0.90 percent – from 2134.50 just before the debate to 2153.75 at the end of the night. Dow Jones Industrial Average and Nasdaq futures also shot up by a similar percentage, with the Dow jumping from 17,984 to 18,127 and the Nasdaq from 4,804 to 4,845.

The following day, September 27th, the S&P sprinted 1.1 percent higher in a sign of market jubilation.

These numbers were the clearest U.S. stock market reaction to the presidential debate, but by no means is it the only investor response to Trump.

The Mexican peso has emerged as the clearest indicator of Trump’s electoral fortunes – plummeting when Trump rises in the polls and rallying when he falls.

“This ebb and flow of political news and who’s beating who is going to have an effect not only on our domestic markets, but if you look at the peso, it’s been taken to the cleaners as Trump had risen in the polls,” said Henry Peabody, portfolio manager at Eaton Vance.

As that “chaos candidate,” as Jeb Bush called him, had clawed his way to within striking distance of the presidency, he deflated the Mexican peso by 10 percent in 2016 as he climbed.

The peso got its revenge during the debate, as investors bet on the currency. It rocketed 2.48 percent in value against the dollar from September 26th to the 27th. Before the debate, it took 19.87 pesos to buy a U.S. dollar. After the debate, that figure was 19.39 pesos.

Trump has maintained his two clearest policy positions – that he would renegotiate the North American Free Trade Agreement and build a $10 billion wall between the U.S. and Mexico that he’d force the Latin American country to pay for.

“A significant part of Mexican peso underperformance cannot be attributed to global macro factors and likely reflects a ‘U.S. elections premium,’” Goldman Sachs analysts Mark Ozerov and Kamakshya Trivedi said in a recent note to clients.

Ahead of the second presidential debate, the peso strengthened by almost 2 percent against the dollar, as Trump’s candidacy started to unravel.

The revelation of Trump’s lewd “Access Hollywood” audio recording prompted scores of Republican office holders and aspirants to revoke their support of Trump’s candidacy.

Even before that lascivious tape, Trump floundered as rival Hillary Clinton started to run away in the polls. She widened her national lead to 4.6 points in a race that used to be on a razor’s edge.

It’s a development that gives investors confidence.

“Trump brings more uncertainty. Clinton is a known quantity. Just not knowing that much of Trump’s plan makes him more uncertain,” said David Lebovitz, a vice president and global market strategist at JP Morgan, in an appearance on CNBC.

Investors aren’t just betting against Trump because he sounds crazy now, but because he could be a real economic threat in the future.

Trump’s election would bring a far bigger market correction than any president in modern history.

Economist Justin Wolfers created a formula to determine what Trump’s effect on the stock market would be should he be elected. Wolfers’ prediction is that stocks will plummet 10 to 12 percent in value if Trump won.

Oxford Economics research has found that Trump’s economic policies would cost the U.S. 5 percent in potential GDP growth by 2021. Ultimately, he could cost the American economy $1 trillion in lost growth.

But not every investor is worried.

“Whether we get one or the other president, they’re going to have an oppositional legislature that would prevent them from enacting any policies that would be the real game-changers,” Jason Pride, director of investment strategy at Glenmede Trust Company, said in a CNBC appearance.

Trump and Clinton have both pledged more government spending on infrastructure, which would be beneficial.

But for many investors, including Yusko, the CEO of Morgan Creek Capital Management, Trump’s risks far outweigh his rewards.

“Investors are very worried about what that means for foreign policy, for trade policy, for taxes,” Yusko said.