the richest man in the world Elon Musk, is known for sharing cryptic messages with its more than 100 million Twitter Inc TWTR Follower. A recent post could be a dig at investors betting against electric vehicle companies Tesla Inc TSLA.

What happened: Elon Musk on Friday night tweeted three simple words “Shortville heatwave”. The tweet also included a hot face emoji. While the tweet came as temperatures hit 101 degrees in Austin, Texas, home of a Tesla Gigafactory and Musk, it likely had nothing to do with the weather.

Instead, the tweet is likely referring to short sellers or those betting against Tesla stock.

Sawyer Merrittwho frequently publishes news about the electric vehicle industry asked in response if “anyone checked how Bill Gates is doing?”

Bill Gates recently had a $500 million bet against Tesla stock.

Related link: Leaked chats show Musk confronted Bill Gates for shorting Tesla: Here’s what was discussed

Why it matters: Musk’s contribution comes as Tesla stock has seen some positive momentum. Tesla shares are up 31% over the past month and over 10% in the past five days.

On July 22nd the time had come reported that Tesla short sellers suffered a $1 billion loss; and S3 Partners predicted a short squeeze on the electric vehicle company’s shares could occur.

The positive gains for Tesla stock over the past month came as AXS Investments launched a single-stock inverse ETF, allowing investors to bet against Tesla’s performance.

That AXS TSLA Bear Daily ETF TSLQ was started two weeks ago and is down 23% since launch.

Musk isn’t the only CEO taking on short sellers on Twitter. AMC Entertainment Holdings AMC chairman Adam Aaron Has Posted several times about people betting against AMC and the cinema industry while using the #ChokeonThat hashtag. Aron also suggested that a short squeeze might come around use the expression “wen pounce” in reference to AMC’s upcoming earnings report.

TSLA Price Action: Tesla shares closed at $891.45 on Friday, up by…