Elon Musk purchased 2.57 million Tesla shares last week, boosting the stock by 8% in premarket trading. The $1 billion investment signals Musk’s focus on Tesla’s move into artificial intelligence. The move is seen as a vote of confidence by investors, as Tesla has faced challenges this year. Tesla also proposed a long-term pay package for Musk that could reach $1 trillion. Shares of Tesla are down 2% year-to-date.

Read more at Yahoo Finance: Tesla Stock Soars as Elon Musk Buys About $1B Worth of Shares