Elon Musk takes a dig at short sellers on a big day for Tesla's stock

Tesla CEO Elon Musk is going after the short sellers. 

Musk tweeted, "Stormy weather in Shortville ..." on Monday, in an apparent jab at traders who shorted the stock, or bet that it would fall. 

It's been a tough couple of months to be short Tesla shares, as they have gained nearly 30% this year. On Monday, shares were up 4% after news that Tesla made a record number of deliveries in the first quarter. Deliveries rose 69% to 25,000, rebounding after delays in the previous quarter, according to a company release on Sunday.   

Tesla's gain made it bigger than Ford by market cap for the first time. 

By February, traders who were betting against Tesla suffered a loss of 31%, or $2.3 billion when taking into account financing costs, according to S3 Partners, a financial analytics firm. Short interest climbed to more than 35% of the float, or shares available to the public, in the weeks after Tesla announced in January that it missed its 2016 deliveries target.

Musk's tweet was a lot more subtle than how some other CEOs have responded to short sellers. For example, AthenaHealth CEO Jonathan Bush told Bloomberg TV "I'm already rich, who cares" in 2015 as part of a response to why the company was the most shorted stock.