The sales so far were considerably short of the $20 billion worth he promised over the weekend that he would sell.
Elon Musk, the chief executive of Tesla, disclosed on Wednesday that he had sold about $5 billion worth of Tesla shares, in part to cover his tax obligations after exercising options on a large tranche of stock.
Mr. Musk sold about 4.5 million shares between Monday and Wednesday, according to filings with the Securities and Exchange Commission. Tesla’s stock closed trading on Wednesday at $1,067.95, which would value the shares at about $4.8 billion, but some were sold for slightly higher prices.
In the filings, Mr. Musk said he had sold about a million of the shares “solely” to cover taxes on 2,154,572 in stock he picked up at $6.24 each. Those shares he acquired, for a total of $13.4 million, were instantly worth about $2.3 billion. Later Wednesday, he disclosed the sale of an additional 3.6 million shares.
Mr. Musk still owns nearly 17 percent of Tesla’s stock, shares worth about $180 billion. Tesla recently passed $1 trillion in market valuation.
Over the weekend, Mr. Musk posted a poll to Twitter asking his followers whether he should sell 10 percent of his stock, referring to a political debate over whether the wealthiest Americans should be taxed according to their wealth rather than their income. He said he would abide by whatever respondents chose, and about 58 percent said to sell.
Regardless of the poll, the disclosures indicated that Mr. Musk had put a plan in place in September to sell shares when buying options. Mr. Musk holds more than 20 million stock options, worth nearly $30 billion, that expire in August. Many of those options are unlikely to qualify for preferential tax treatment, meaning he could owe billions of dollars in taxes if he exercises all of them.
Tesla’s stock slid 16 percent in the two days of trading after his Twitter post, though it gained 4.3 percent on Wednesday before Mr. Musk disclosed his trades. Tesla’s shares were up in aftermarket trading following his disclosures.
Stephen Gandel contributed reporting.