Brandon Bell / Getty Images Elon Musk purchased some 2.57 million Tesla shares last week, sending the stock higher in early trading Key Takeaways Elon Musk purchased some 2.57 million Tesla shares last week, sending the stock higher in early trading. The CEO's investment was worth approximately $1 billion. The move is seen as a sign Musk is more focused on Tesla and its move into artificial intelligence. Tesla (TSLA) shares surged 8% in premarket trading Monday after it was revealed CEO Elon Musk ...