Elon Musk's most hated group of investors are ratcheting up their bets against Tesla ahead of the company's earnings

• Bets against Tesla's stock price are at their highest point of 2019 so far as the company gears up to report its first-quarter earnings.
• Tesla has long been one of the most heavily shorted stocks in the world.
• CEO Elon Musk, meanwhile, has long derided short sellers who bet against Tesla's stock price.

Tesla is gearing up to report its first-quarter earnings on Wednesday.

Meanwhile, investors were ratcheting up their bets that the company's stock price will decline following the report that CEO Elon Musk has warned there will be another slip back into the red for Tesla.

Short-interest data from S3 Partners shows that bets against Tesla are at their highest total since the beginning of 2019, at $8.9 billion with the stock coming in as the largest automotive short worldwide.

Tesla's stock, meanwhile, has fallen nearly 15% since the beginning of the year, as store closings, a disappointing first-quarter deliveries report, and fears for the company's ongoing financial stability weigh on investors' minds.

In the latest 3.6% decline since Monday, short-sellers have made $334 million in profits, according to S3.

"We should see short sellers topping off their bets [on Wednesday], if they feel TSLA will report a quarterly loss following a delivery shortfall in its first quarter," Ihor Dusaniwsky, managing director of predictive analytics at S3, said in the report.

Tesla's not only the most popular short target for professional investors, but also amateur traders who can mimic their directional bets through options contracts on retail brokerages. On Twitter, an army of Tesla skeptics that call themselves $TSLAQ has gained a massive following in recent months, much to Musk's chagrin.

Read more: Inside Tesla Twitter, where legendary short-sellers and amateur investors gather to trash and praise Elon Musk's electric empire (TSLA)

The billionaire has spoken many times of his hatred of short sellers: "They want us to die so badly they can taste it," he tweeted in June 2017.

"When CEOs criticize short-selling, it's usually because they're looking to deflect blame for their own failings and obscure the uncomfortable truth that their long-holders are losing confidence and are selling," the short-seller Carson Block, who founded Muddy Waters Capital, told Business Insider last year.

Tesla's first-quarter earnings are expected shortly after markets close on Wednesday.

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Get the latest Tesla stock price here.