President Trump knows a lot of voters don’t like him. But detractors should vote for him anyway, Trump says, for one crucial reason: To protect their savings.

“If for some reason I wouldn’t have won the [2016] election, these markets would have crashed. That’ll happen even more so in 2020,” Trump told the crowd recently at a rally in New Hampshire. “You have no choice but to vote for me because your 401(k), everything is going to be down the tubes. So whether you love me or hate me, you’ve got to vote for me.”

The allegation is clear: Democrats are bad for the stock market, so if a Democrat beats Trump in 2020, stocks will tank and every American with a portfolio will lose money. Like many Trumpisms, however, the claim does not survive a comparison with the facts.

Democrats, in reality, are good for the stock market. The S&P 500 has risen by about 28% since Trump’s inauguration in 2017. That’s okay. But it rose 34% during the same period of time in Barack Obama’s first term, and 41% during the same period of time in Obama’s second term. Here are the numbers going back to Richard Nixon’s first term:

Trump’s comparison with Obama improves if you measure stock-market gains since each president’s election, rather than Inauguration Day. The S&P 500 is up 35% since Trump’s election in 2016, compared with 13% for Obama’s first term and 47% for Obama’s second term. But Trump’s 35% gain since Election Day still trails the average for Dems since 1968, which is 37%. The average gain since Election Day under Republican presidents is just 18%.

It’s well known among stock-market geeks that stocks do better under Democratic presidents than under Republicans. That’s probably just random, however. Many factors influence stocks—most importantly, the overall state of the economy and the business cycle. These days, the Federal Reserve has more power over the direction of stocks than any president does. Presidents, in fact, rarely change policies in ways that send stocks moving one direction or the other.

Many investors thought Trump might be different. Stocks rose sharply after his surprise election in 2016, and performed strongly in 2017. But since the beginning of 2018, the S&P 500 has been relatively flat. Trump’s tax cuts and deregulatory policy may have helped stock values, but his protectionist trade policy has countermanded that. And many other factors, including a slowing global economy, have kept a lid on stock prices for the last 18 months.

If a reformist Democrat such as Elizabeth Warren or Bernie Sanders got elected president, it could depress stocks, since each favors a variety of policies that would essentially transfer wealth from corporate interests to lower- and middle-income Americans. But such a scenario is somewhat self-preventing, since Americans are unlikely to elect a candidate who might harm financial markets and by extension the broader economy, even if those candidates are popular in a liberal subset of the Democratic party.