Stocks soared Thursday after the Federal Reserve cut interest rates by 50 basis points the day before. One of the biggest winners was Tesla (NASDAQ: TSLA). Shares jumped 7.4% as investors saw the rate cuts as a clear tailwind for the U.S.'s largest electric vehicle (EV) maker. That gain was enough to add $50 billion to its market cap.

US tech billionaire Elon Musk has not developed a product that can cut household energy consumption by up to 90 percent, nor has the Department of Justice sued to prevent its release, despite claims in social media advertisements.