(CN) - A surge by Donald Trump in the polls is roiling financial markets worldwide, as investors have begun to rethink their certainty of a victory by Hillary Clinton.
The Vix Index, a measure of anticipated U.S. stock market volatility compiled by the Chicago Board Options Exchange, is nearing highs last seen following the United Kingdom's vote to leave the European Union last summer.
The index, informally known as Wall Street's "fear gauge," is a measure of the implied volatility of the Standard & Poor's 500 Index.
The S&P 500 encompasses 500 top companies in leading U.S. industries. Many mutual funds use it as the benchmark they measure their own performance against.
Investors generally see Clinton as surer bet on future stock performance than Trump because they are familiar with her long public career and feel more certain of what her future policy decisions might be.
The prospect of a Trump victory brings with it more uncertainty, both because the shoot-from-the-hip billionaire real estate mogul is new to politics and governing, and because his winning would bring a change in the political party that has held the White House for the past eight years.
On Tuesday, an ABC News/Washington Post tracking poll showed Trump with a 1 point lead over Clinton nationally the first time the Republican has had a lead in that poll since May. On Wednesday morning the same poll declared the race a tie.
Economists said Wednesday that traders fear being caught on the wrong side of history and are beginning to react to the prospect of change by moving their money into safe havens like gold.
On Wednesday morning, the European Stoxx 600 index declined 0.8 percent to its lowest level since July.
In Asia, meanwhile, Japan's Nikkei 225 index lost 1.8 percent and the Hang Seng, in Hong Kong dropped 1.4 percent.
The uncertainty in the election's outcome also exerted pressure on the Dollar Index a measure of the strength of U.S. currency compared to several international currencies pushing it down 0.3 percent Wednesday morning.
But that comes after an even larger drop of 0.8 percent on Tuesday, after a slew of polls showed enthusiasm for Clinton sliding and Trump ascending.
Another interesting measure of how the current state of the presidential race is effecting markets can be found in the Iowa Electronic Market, a futures market run for research and teaching purposes by the University of Iowa.
It currently says the implied probability of Clinton a majority of the popular vote is 64.2 percent. Last week, the probability of her winning a majority of the popular vote was 89.5 percent.