On the flip side, some investors are buying oil exploration, defense and aerospace stocks, and banks that are expected to benefit if Mr. Trump prevails. And a stock-like instrument called the “trade war” fund, with exposure to companies that would be affected by the impact of new or changing tariffs, attracted substantial attention before being liquidated and converted into a private investment vehicle.

“Market participants agree that the U.S. election is the big event for 2020,” Amelia Garnett, a salesperson in Goldman Sachs’s securities division, said on a recent podcast. The financial industry views Ms. Warren in particular with apprehension, and her rise in the polls during the late summer and fall, Ms. Garnett added, inspired “a rapid flurry of interest” from clients to prepare for the possible impact of the type of higher-tax, bigger-government agenda Ms. Warren has promised.

The goal for investors, of course, is to make money off their wagers — or at least to avoid losing it due to some unforeseen political outcome. But some analysts say the performance of these politically oriented portfolios may also be a leading indicator of public opinion as the country braces for what’s likely to be a volatile election year.

“The idea is this: we’re going to end up either on the very left or the very right with this election,” said Ben Emons, an investment strategist at Medley Global Advisors who has been fine-tuning the candidate baskets in recent months. “The market will trade it,” Mr. Emons added, “because the market will price in the probabilities around these outcomes.”

Although the investment focus for progressive candidates has been on stocks to sell, analysts say there is also a reverse case involving stocks to buy. Those, according to Mr. Emons, could be in areas that Ms. Warren’s policies, for example, would expand — child-care providers like Bright Horizons Family Solutions, for instance, or green energy providers like Brookfield Renewable Partners. Although stocks to sell in a second term for President Trump have been less of an investor focus, Mr. Emons said that media stocks could fall under that category, given that news organizations are subject to frequent attacks from the president.