The tone is shifting on Wall Street, where many analysts have gone from taking the U.S. presidential election largely in stride to expressing concern about the lack of investor preparedness.

Analysts warned ahead of Monday evening’s first-of-three debate between Democratic nominee Hillary Clinton and the Republican standard-bearer Donald Trump that it could cause turbulence or even sock stocks. After the event was all said and done, financial markets declared Clinton winner of the debate as stock futures rallied, pointing to an upbeat start for Wall Street Tuesday.

Goldman Sachs had described the debate in a note Monday as “the biggest matchup since the Mayweather/Pacquiao bout.” (For non-boxing fans, that May 2015 match was billed as “The Fight of the Century.”) In other words, Goldman — like other investment banks — is taking this election more seriously by the day.

With two more debates and just 41 days before the U.S. election, Goldman and others are telling investors it’s time to get ready.

The first presidential debate: what to watch

David Kostin, chief U.S. equity strategist, and his Goldman team came out with some pre-election tips for investors, noting that central-bank policy is another issue roiling investors right now. The advice:

• Protect against the likely rise in equity uncertainty ahead of the U.S. presidential election.

• Buy companies with big government revenue exposure.

• Take the weak performance of defensives as a buying opportunity.

Public spending will likely increase no matter who wins, according to Kostin, adding that investors should seek out defense stocks and construction materials providers. Vulcan Materials Co. VMC, +1.38% , Martin Marietta Materials Inc. MLM, +1.44% , Summit Materials Inc. SUM, +2.15% and Eagle Materials Inc. EXP, +1.79% are names the Goldman team likes.

On the flip side, health care could be risky business after this election, given Clinton’s criticism of drug pricing and Trump’s opposition to the Affordable Care Act. Alternative energy and fossil fuels, financial-services regulation, minimum-wage hikes and trade policy are other themes with potential investment implications.

As for central banks, after the Federal Reserve and Bank of Japan meetings last week, Kostin said that if interest rates remain low, defensive stocks will likely rebound owing to their high dividend yields and mostly stable earnings. That sector is hugely underweighted by mutual- and hedge-fund portfolios, Goldman noted.

‘Oh, my God, this is bad’: Among the worriers on Wall Street ahead of the U.S. election, Erik F. Nielsen, group chief economist at UniCredit Research, had strong words about a market he said was far from fully bracing for the possibility of Republican nominee Trump winning the November presidential election.

Nielsen suggested that the markets woke up to a Trump-as-president possibility for the first time on the Monday after the Sept. 11 terror attack anniversary. That’s when Clinton was sidelined with walking pneumonia that seemed to intensify speculation about her overall health — concerns Nielsen said showed up in the polls.

“But while opinion polls [have] continued to slide in that direction, making it now uncomfortably difficult to guess the outcome of the election (Hillary is still slightly ahead when you go down into the details of swing states and the Electoral College), I have been amazed by how markets don’t seem to take much notice,” said Nielsen.

Nielsen said his conversations with European investors fall into three “categories”:

• Oh, my God, this is bad.

• This is not good, but the American democracy’s checks and balances are strong enough to prevent him from doing too crazy things.

• Maybe he’ll be like Ronald Reagan.

The economist said he’s firmly in camp No. 1, with his single biggest concern a “complete lack of knowledge” as to what Trump’s policies might entail. The fact that the candidate doesn’t have an economic- or foreign-policy adviser with a known record of publication or views in the field at his disposal marks a troubling first in modern history, Nielsen said.

If the likelihood of a Trump presidency “increases in coming weeks, then you need to start questioning the Fed’s intentions [with interest-rate policy] for December, and you’ll want to reduce your exposure to, particularly, U.S. equities and the dollar,” he said.

Jasper Lawler, market analyst at CMC Markets, said in a note to clients Monday that a number of forecasters have raised the odds of a Trump presidency.

And Citi, which early last week raised its forecast possibility of such an outcome to 40% from 35%, said in its fourth-quarter commodities update released Monday that uncertainty around the U.S. elections, along with the possibility of a Fed interest-rate increase, will spell volatility for both foreign exchange and gold markets.

The analysts said gold US:GCZ6 could trade sideways between $1,300 and $1,350 an ounce until the Fed decision in December, but prices could crest above year-to-date peaks in a “knee-jerk move” if Trump wins the election.

How to position a portfolio ahead of the Nov. 8 election remains tricky for some, noted FXTM’s chief market strategist, Hussein Sayed. “Nasdaq’s Biotech index plunged 4.5% in two days [Aug. 24 and 25] in one tweet from Hillary Clinton criticizing the recent price hikes on EpiPens, which suggest that investors and portfolio managers are seriously considering having different asset allocation strategies on the outcome of the election,” said Sayed.