Tesla Inc chief executive officer Elon Musk unloaded US$5bil of stock in the electric car-maker, shortly after holding a poll on Twitter over whether he should sell 10% of his massive stake in the company.

The world’s richest person so far has disposed of more than 4.5 million shares this week, according to regulatory filings Wednesday - his first sales in more than five years.

On Monday, he offloaded about US$1.1bil worth of stock to pay income taxes on equity options that he also exercised that day, two of the filings showed. Those transactions were made based on a pre-arranged trading plan adopted in mid-September.

On Tuesday and Wednesday, Musk carried out the remaining sales. The filings detailing those disposals didn’t indicate that they were pre-planned.

The documents shed no light on whether Musk’s weekend Twitter poll had any bearing on his decision to carry out some or all of the transactions - or whether he’ll continue selling until he’s met the 10% threshold. To get there, he’d have to get rid of roughly 17 million shares, and even more if he also includes exercisable options in his total holdings.

The options Musk exercised came from a big award he received in 2012. He would have had to exercise them before August of next year, or they’d expire. Taxes on such transactions are usually covered by immediately disposing of some of the newly acquired shares. Earlier this year, Musk said publicly that he likely would exercise options earned from the 2012 award in the near future.

It’s possible that the option exercises and related sales would have been executed regardless of the Twitter poll’s outcome, given that they were made under a pre-arranged plan. But the terms of such plans aren’t subject to public disclosure, and executives have wide latitude to cancel or modify them at any time.

Still, the headline-grabbing Twitter referendum pummeled Tesla’s shares on Monday and Tuesday, wiping out US$50bil from Musk’s net worth. Tesla rose 4.3% on Nov 10 to close at US$1,067.95 , paring losses this week to less than 13%. After the first few trades were disclosed, the stock rose 2.7% in post-market trading.

The billionaire last sold shares in 2016, when he exercised options and liquidated some of the newly acquired stock to cover about US$590mil of income taxes.

In his announcement of the Nov 6 poll, Musk wrote that “much is made lately of unrealised gains being a means of tax avoidance, so I propose selling 10% of my Tesla stock”. Almost 58% of the 3.5 million votes were cast in favour of a sale.

Musk, 50, is the world’s richest person with an almost US$300bil fortune, according to the Bloomberg Billionaires Index.

 - Bloomberg