With fewer than six weeks to go before the US election, investors are starting to get antsy. Recent comments from President Donald Trump aren’t helping.

Trump failed to commit on Wednesday to a peaceful transition of power after Election Day, fueling concerns he may not relinquish his office should he lose in November.

“Well, we’re going to have to see what happens,” Trump said.

The political and democratic implications of such a comment merit their own debate. For Wall Street, however, it feeds fears that a contested election result and a potential constitutional crisis could spark weeks of uncertainty at a delicate moment for markets.

Though they’re still up dramatically from March lows, stocks have been shaky this week. The S&P 500 fell 2.4% on Tuesday, and the index closed lower in five of the past six trading sessions.

“From Covid infection spikes to worries that central banks are out of ammunition, and on to concerns about how much fiscal easing is available, not to mention the uncertainty around the US election, there’s plenty of fuel to feed to the current risk aversion,” Societe Generale strategist Kit Juckes told clients on Thursday.

Investors are showing increasing signs of alarm about what could happen in November; expectations of volatility, as measured by options markets, have shot up recently, per Brad McMillan, chief investment officer at Commonwealth Financial Network.

The specific impact of a disputed election is difficult to map out, and strategists note that the length of any period of uncertainty about who will take the White House is crucial.

“The effects likely will be real and substantial, but also temporary,” McMillan said.

The clearest analogue for what could happen is the 2000 election, when the Supreme Court had to weigh in on whether to let a recount continue in Florida. Despite breathless media coverage, the market reaction was muted.

The 2020 election could be different — both because of the political players and because of the economic shock caused by the pandemic.

“The risk of stronger market reactions cannot be dismissed,” Commerzbank economists said in a note to clients this week. “Domestic political rifts have become much deeper.”

Not just stocks: Commerzbank warns that in a situation where the loser does not concede the election, the US dollar — which has already shed more than 5% since the beginning of July — would especially suffer.