JPMorgan Chase & Co. reportedly has warned savvy investors that Tesla shares will tumble more than 40 percent before the end of the year.

JPMorgan reaffirmed its underweight rating on Tesla shares, saying other automakers may price their electric cars aggressively, CNBC reported.

The bank’s analyst is cautious over the company’s second-quarter financial numbers such as free cash flow and profit margin, CNBC said.

Tesla has a “highly differentiated business model, appealing product portfolio, and leading-edge technology, which we believe are more than offset by above-average execution risk and valuation that seems to be pricing in a lot,” analyst Ryan Brinkman said in a note to clients Friday.

“We have highlighted more concerns regarding increased competition, including from automakers looking to use the sale of battery electric vehicles to subsidize their more lucrative internal combustion engine portfolio vehicles from a legal, regulatory, and compliance perspective, rather than trying to generate profit on the sale of these battery electric vehicles in and of themselves.”

Brinkman reaffirmed his $180 December 2018 price target for Tesla shares, representing 44 percent downside from Thursday’s close, CNBC reported. Tesla shares (TSLA) were down $7.28, or 2.3 percent, at $312.95 just after midday Friday.

Meanwhile, Gene Munster, a managing partner at venture capital firm Loup Ventures, wrote an open letter to Tesla’s chief executive officer to tell Elon Musk that his conduct the last six month has been concerning and is shaking investor confidence.

“Your behavior is fueling an unhelpful perception of your leadership — thin-skinned and short-tempered,” Munster wrote, Bloomberg explained.

Munster cited Musk’s outburst at analysts on Tesla’s first-quarter earnings call; his ongoing frustration with short sellers and the media; a June email exchange with a former employee, whom Musk had accused of being a saboteur; and tweets in which the CEO called a cave explorer who helped rescue a dozen boys in Thailand last week a pedophile.

A longtime technology analyst known for his calls on Apple Inc., Munster couched his criticisms with some commendation. He said Musk’s record as a visionary is “unprecedented” and praised him for “building a culture of walking through walls and inspiring a workforce to a level I have not seen in over 20 years of covering tech.”

Munster wrote the letter at the urging of investors who are supportive of Tesla and believe in Musk, he said in a Bloomberg Television interview. “He has a great opportunity but he is jeopardizing the opportunity,” Munster said of the CEO.

Tesla shares fell Monday after Musk, 47, attacked a volunteer who played a key role in organizing the rescue of a Thai youth soccer team. British diver Vern Unsworth had dismissed the “kid-size submarine” Musk’s Space Exploration Technologies Corp. built to try to help as impractical and called it a “PR stunt” in an interview with CNN.

(Newsmax wire services contributed to this report).