The world’s richest man has again sold Tesla shares to earn cash but has yet to explain for doing so just days after laying off approximately half of Twitter’s employees.

After completing his takeover of Twitter, Elon Musk sold about $4 billion (£3.46 billion) in Tesla stock.

According to documents with the US Securities and Exchange Commission, the founder and chief executive officer of the electric vehicle manufacturer sold 19.5 million shares between Friday and Tuesday.

The reason for the transaction was not stated, although Reuters reports that Musk’s remaining stake in Tesla is approximately 14%.

Along with many other so-called growth stocks, Tesla’s stock price has fallen by about half this year. These firms are viewed as vulnerable to the deteriorating global economy and especially rising levels of inflation.

However, Tesla’s value also reflects a succession of sales by Musk himself to fund the $44bn Twitter acquisition and a broader worry among shareholders that Tesla will lose focus now that the Tesla/Twitter/SpaceX tycoon has additional time demands.

Analysts anticipated that Musk would sell further Tesla shares to fund the Twitter acquisition.

He had promised to fund $46.5 billion in stock and loan finance for the transaction, which was sufficient to cover the $44 billion price tag and closing charges.

The bank’s Morgan Stanley and Bank of America have contributed $13 billion in loan funding.

Musk’s $33.5bn equity pledge included his own 9.6% Twitter ownership, valued at $4bn, and the $7.1bn he had acquired from equity investors, including Larry Ellison of Oracle.

Despite uncertainties that caused him to back out of the transaction in May, he completed the sale last month. Since then, he has laid off almost half the employees and announced that he will charge $8 per month for blue check marks to validate the authenticity of a user’s account.

Musk had not yet commented on why he sold Tesla shares.