Elon Musk, the multibillionaire founder and chief executive of electric car company Tesla, has joined those protesting against the coronavirus lockdown of the US economy, tweeting: “FREE AMERICA NOW”.

His outburst came as he was close to securing a $750m (£585m) payout from a bonus scheme linked to Tesla’s share price.

Musk, the world’s 22nd-richest person with an estimated $38.5bn (£30.5bn) fortune, on Wednesday tweeted: “Give people their freedom back!” with a link to a Wall Street Journal article suggesting that the lockdowns have not saved that many lives but have shattered local economies.

He also tweeted: “Bravo Texas!” with a link to a local newspaper story about the Texas governor Greg Abbott’s plans to allow shops, restaurants and movie theatres to reopen from Friday.

Musk, who has a history of tweeting controversial statements, later clarified that he did not think all shops and businesses should be reopened immediately.

Replying to another user on Twitter he said: “Yes, reopen with care & appropriate protection, but don’t everyone under de facto house arrest”.

His outburst came a day after Tesla was forced to delay the planned reopening of its electric car factory in Fremont, California, after six Bay Area counties extended the lockdown until the end of May. Tesla had been planning on reopening the factory on 4 May, when the lockdown order was supposed to be lifted. The factory has been shut since 23 March.

Despite the closure, Telsa’s share price has recovered nearly all of the slump caused by the coronavirus outbreak. The rebound in the shares to $769 on Tuesday, from a low of $361 on 18 March, puts Musk close to achieving a $720m payday.

The rally in the share price puts Tesla’s market capitalisation at $141bn; the company has reached a six-month average valuation of $96bn. If the market cap achieves a six-month average of $100bn it would trigger the vesting of the first of 12 tranches of share options granted to Musk.

Each tranche gives Musk the option to buy 1.69m Tesla shares at $350.02 each. If Musk sold those shares at Tuesday’s closing price of $769 he could make a profit of about $750m.

Musk’s paper fortune has risen by more than $10bn so far this year.