Jeff Bezos sold Amazon shares worth $8.5 billion in multiple transactions this month. Meanwhile, Jamie Dimon, chairman and CEO of JPMorgan Chase, sold $150 million in stock last week, his first cash-out since taking the top job at the bank 18 years ago. Around the same time, Leon Black, cofounder and former CEO of Apollo Global Management, shed $172.8 million in stock—also a first-ever stock sale. 

In dozens of trades since the beginning of February, Mark Zuckerberg unloaded about 1.4 million shares of Meta stock worth roughly $638 million, according to an analysis from insider stock sales data firm Verity. This latest batch of sales came after previously culling 588,200 shares in November, 688,400 in December, and 447,200 in January. He sold nearly $600 million worth in the three months leading up to February, and his proceeds from combined sales during the past four months have reached $1.2 billion. 

Similarly, the trust for the Walton family, heirs to Walmart’s founder, sold $1.5 billion in Walmart stock this month. The family owns about 45% of Walmart’s shares, according to Bloomberg.

Many of the sales were made according to 10b5-1 trading plans that the executives set up late last year and early this year. These trading plans are created in advance so that shares are automatically sold by a broker at a specific date or when the stock hits a certain price. They’re set up to be triggered at a time when the executive doesn’t possess material nonpublic information that could potentially move the stock price and gives the executive a defense against potential insider-trading charges by regulators.

The sales come as the S&P 500 index is at an all-time high, rising 28% in the past year. The Nasdaq Composite index is up nearly 40% the past year. 

Black, of Apollo Global Management, was the one founder of the bunch to sell outside of a 10b5-1 trading plan. His spokesperson said that the trade was made as part of routine tax and estate planning and to boost the growth of his family office, Elysium Management. The Walton family’s sales were also outside of a 10b5-1 plan. A 2015 statement from the Walton family said that its members will sell shares from “time to time” to curb increases in its ownership of the retail giant. The Waltons set up the trust that same year and told Walmart that it had no set timetable for sales of company stock.

Calm before the storm

Alan Johnson, a compensation consultant who works with financial services firms, said the stock sales could be the result of the election possibly shaking things up in the fall. Thus, if an executive is currently “more in the money” than expected, diversifying their holdings is a good idea. Plus, wealthy stockholders may be taking advantage of tax breaks implemented during the Trump administration, noted Johnson, in case they are eliminated under any new administration or Congress after the upcoming elections.

“If you’re reading the tea leaves and looking at what may happen with our politics in the next year or so, things are pretty good right now—the markets are up,” said Johnson, president of Johnson Associates. “With our politics and everything else going on geopolitically, maybe it won’t be as good a year from now or two years from now.”

As for Dimon, Johnson said the bank CEO is known for holding stock in the company, a tactic that has enriched him. Dimon’s net worth according to Forbes is $2.1 billion.

“The way he of course became fabulously wealthy was to get the stock, keep it, and have the stock price go up,” said Johnson. “What’s unusual about him selling is he’s doing it so late in his career.”

Most executives would have sold moderate amounts along the way, he explained. That doesn’t necessarily mean anything about Dimon’s tenure at the bank potentially having an end date, said Johnson.

“A joke I’ve used with clients is that, looking back 10 years from now, one of the questions we’ll be asking is, ‘Who is going to replace Jamie Dimon at JPMorgan?’” he said. “We’ve been asking that question for 10 years already.”