Shares topped out at $304 shortly after the start of trading and stayed above the $300 mark on into the afternoon.

Their latest record high continues a torrent of buying that started Monday after Tesla released an encouraging car delivery report. Since yesterday’s opening bell, the stock is up 9% on trading volume that more than doubles its normal level. The good news has even gotten a rise out of Tesla founder Elon Musk, who took to Twitter Monday to troll short sellers.

The sharp increase moves Tesla closer to surpassing General Motors as the most valuable U.S. car maker. Monday’s rally pushed Tesla’s market cap past Ford’s $45.3 billion valuation for the first time and set up the potential for a changing of the guard of sorts. GM currently has a market cap of $51.25 billion, which is almost $2 billion more than Tesla’s $49.3 billion. Another strong market day or two for Tesla could drive its market cap past the last domestic car manufacturer standing in front of it—despite the fact that Tesla produces far fewer vehicles than either Ford or GM.

The automaker delivered just 76,000 cars to customers in 2016, compared with 6.7 million for Ford and 10 million for GM. But Tesla’s low production numbers don’t reflect a lack of demand, merely lack of manufacturing capability. It can take years for customers to receive a car they ordered from Tesla, which is discouraging to some but also adds to the company’s mystique. For instance, Tesla’s upcoming Model 3, which is slated to start being delivered later this year, received around 200,000 preorders the first day customers could place one, despite extensive waiting time for the cars to be ready.

Tesla’s stock price has been on a tear over the last year or so. Since dipping below $145 in February 2016, shares hase gained 109%. Thanks in part to the past two days of gains, Tesla is up nearly 25% since it closed at a low of $243.69 on March 10 and has gained nearly 40% for the year to date.