Tesla chief executive Elon Musk has sold around $5bn (£3.7bn) of shares in the electric carmaker.
It comes days after he asked his 63 million Twitter followers whether he should sell 10% of his stake in Tesla.
The company’s shares fell by around 16% in the two days after the poll came out in favour of him selling shares, before regaining some ground on Wednesday.
Tesla is the world’s most valuable carmaker, with a stock market valuation of more than $1tn.
Mr Musk’s trust sold almost 3.6 million shares in Tesla, worth around $4bn.
He also sold another 934,000 shares for about $1.1bn after exercising options to acquire nearly 2.2 million shares, according to filings with the US stock market regulator.
The documents showed that the sale of about a fifth of the shares was made based on a pre-arranged trading plan set up in September, long before Mr Musk’s social media posts at the weekend about selling some of his shares.
However, the regulatory filings also showed that the sale of the remainder of the shares had not been scheduled.
Mr Musk has highlighted that he is not paid in cash by Tesla and only has stock.
Part of the latest transaction saw him exercising stock options that he was awarded as part of his pay package in 2012, which is due to expire in August next year.
Mr Musk has one option to buy 22.86 million Tesla shares at $6.24 each, but if he doesn’t exercise the stock option then the shares would become worthless after the expiry date.
Such transactions trigger income taxes, which are typically settled using money raised from immediately selling some of the newly acquired shares.
His move also comes as US Democrats have proposed a so-called “billionaires tax”, which could the richest taxed on “unrealised gains” even if they do not sell any of their stock.
“Elon Musk doesn’t take a salary, he’s paid in big chunks of stock. At some point in time you have to take some of that concentration down,” Art Hogan, chief market strategist at National Securities in New York, told Reuters.
“This is not novel. It just gets more attention because it’s such a high market-cap type, attention grabbing kind of company.”
Before selling some of his shares, Mr Musk owned a 23% stake in Tesla.
The shares he sold equate to about 3% of Musk’s total holdings in the carmaker, though it has not been confirmed if the sale was related to his weekend Twitter poll, or if he intends to stagger further sales.
On Saturday, Mr Musk posted a poll asking his followers to vote on whether he should sell part of his stake in Tesla to meet his tax obligations.
“Much is made lately of unrealised gains being a means of tax avoidance, so I propose selling 10% of my Tesla stock,” he tweeted.
“I will abide by the results of this poll, whichever way it goes.”
The poll attracted more than 3.5 million votes, with nearly 58% voting in favour of the share sale, but Mr Musk has been silent regarding any share sales since the poll.
It was Mr Musk’s first sale of shares since 2016, when he last exercised stock options. At the time he also sold some of the shares to cover an income tax bill of close to $600m.
“The reason that we’re seeing stock rebound is because there does seem to be a method in his madness,” AJ Bell analyst Danni Hewson said.
“It’s about making sure that the market understands this isn’t something done on a whim, or because his Twitter followers told him he should. He’s had his decision already made, rubber stamped.”
Mr Musk is the world’s richest person, with a fortune estimated to be more than $280bn.
