Tesla boss Elon Musk has sold shares in the electric car manufacturer worth around four billion dollars. This emerges from documents from the US Securities and Exchange Commission on Tuesday (local time). Accordingly, Musk sold 19 million shares.

Musk is a co-founder of Tesla and one of the richest people in the world. At the end of October, after a month-long stalemate, he took over the online service Twitter for around $44 billion. The 51-year-old had already sold Tesla shares worth $15.5 billion.

Investors dumped shares of Tesla over concerns about the Tesla CEO's stock sale, causing Elon Musk's net worth to fall below $200 billion on Tuesday, Reuters reported. According to Forbes, the entrepreneur now has a net worth of $194.8 billion.

Wall Street is already concerned that Musk isn't focusing too much on Twitter while neglecting Tesla.

Critics fear that Musk could drastically limit the fight against the spread of hate speech and fake news on Twitter. Those fears were fueled by the firing of around half the Twitter workforce last week.

Musk had recently announced that he wanted to focus more on a paid subscription model on Twitter. He wants to make the platform more independent of advertising revenue.