Musk's tweet, posted early Friday, was a response to comments Einhorn made in a shareholder letter last week, in which he accused Tesla founder Musk of fraud and claimed the "accepted reality appears to be that Elon Musk is above the law".
Einhorn took his letter a step further on Friday, calling out Tesla for its volatile profitability over the last decade compared to Greenlight's history of positive returns.
In Musk's retort, he addressed Einhorn as "Mr. Unicorn", said the letter contained "numerous false allegations".
"It is understandable that you wish to save face with your investors, given the losses you suffered from Tesla's successful third quarter, especially since you've had several down years in performance and a sharp drop in assets under management from $15 billion to $5 billion", Musk wrote.
'Please allow us to send you a small gift of short shorts to help you through this hard time'. "I might learn the difference between your alien dreadnought factory and cars made by hand in a tent".
Musk invited Einhorn, 50, to discuss the company in person, saying his investors "would appreciate you getting smart on Tesla".
Elon Musk is fighting with short sellers again.
In August, Einhorn called on Musk to resign after Business Insider reported on "Project Titan", a Tesla effort to inspect all roofs that had solar panels and potentially faulty connectors.
Einhorn replied on Twitter at the time with a sarcastic thank you, ' and "they did come with some manufacturing defects". The hedge fund billionaire has been a fierce critic of Tesla's finances, and is one of a group of prominent short-sellers with whom Musk has routinely sparred.
The clip on which the Tesla CEO was discussing the future of mankind while smoking marijuana and drinking whiskey on the rocks on a podcast the Joe Rogan Experience went viral previous year and nearly immediately became a meme hit. "Nevertheless, a key contrast is that Greenlight's replace has generated precise profits for our investors since we started in 1996", Einhorn acknowledged.
"I judge facility visits could perhaps be fun (can we originate in Buffalo?)".
On Oct. 23, Tesla documented greater-than-anticipated 3rd quarter results, with a income, excluding a person-time goods, of $1.86 a share, on revenue of $six.3 billion. The carmaker, however, put some concerns to rest after delivering a surprise profit in its third quarter.