Tesla founder Elon Musk is incredulous that short sellers are profiting so much from betting against his company. Reuters/Mike Blake As Tesla's stock enters bear market territory, short sellers are laughing all the way to the bank.

They've raked in a whopping $1.4 billion in profit this week alone as the stock has tumbled 14.6%, its biggest three-day decline since February 2016, according to data compiled by financial analytics firm S3 Partners.

Tesla short sellers have been waiting patiently for a bloodbath like this. Even as the company's stock surged as much as 79% year-to-date through June 23, costing the speculators upwards of $5 billion, they hung tight.

Short interest actually reached a record high of $11 billion as recently mid-June before the traders pared the position slightly. As of Thursday, the measure still sat at nearly $9 billion, according to S3 data.

Tesla's stock price issues started in earnest on Wednesday, when Goldman Sachs said it sees the company's production levels plateauing. As a result, the firm cut its 12-month price target on Tesla from $190 to $180. That's roughly 40% below Thursday's trading price.

It continued on Thursday amid signs of mounting competition. Volvo announced that all of its cars produced during and after 2019 will be either fully electric or hybrid. Additionally, Jaguar is set to release its first electric SUV, a direct competitor to Tesla's Model X, in 2018.

In fact, CEO Elon Musk himself has called his company's valuation into question. Back in May, he told The Guardian, "I do believe this market cap is higher than we have any right to deserve."

But even amid all of this sudden negativity surrounding Tesla's stock, speculators that have held the stock short for all of 2017 have still lost about $3.4 billion year-to-date, S3 finds.

With that in mind, don't expect them to give up their pessimistic view any time soon. While some short sellers may be closing out positions in order to take profit, S3 still sees short interest stabilizing in the $9-10 billion range.

In other words, they've finally seen some results, and they're not stopping now.