Elon Musk, Tesla CEO, took a 9.2% stake in Twitter Inc. to become the social media platform’s biggest shareholder. Musk, the world’s richest man, bought around 73.5 million Twitter shares, according to a document filed with the US Securities and Exchange Commission. This move sent Twitter shares soaring by 26% and came just a week after Musk hinted that he might shake up the social media industry.