(Reuters) - Canada’s BlackBerry Ltd missed Wall Street estimates for fourth-quarter revenue on Tuesday, even as the company said sales of its QNX car software showed improvement. U.S.-listed shares of BlackBerry, which sells security software to companies and governments as well as infotainment software to carmakers, fell nearly 4% in extended trading. Demand for the company’s QNX car software, used by automakers such as Volkswagen and Ford Motor, had been under pressure due to a slow recovery in the U.S. auto industry amid a global semiconductor shortage and pandemic-related weakness. “This has been an exceptional year to navigate, however we are pleased with QNX’s continued recovery, despite new challenges from the global chip shortage,” said Chief Executive Officer John Chen. BlackBerry was also one of the so-called “stonks” that received major attention from investors after a social-media driven retail short squeeze frenzy. The term “stonk” is used to describe stocks with convoluted prospects that are popular with retail traders on online forums. The company’s U.S.-listed shares had gained nearly 41% so far this year. Revenue fell to $210 million in the fourth quarter ended Feb. 28, below analysts’ expectations of $245.1 million, according to IBES data from Refinitiv. Excluding items, the company reported a profit of 3 cents per share, in line with analysts’ estimates. Net loss widened to $315 million, or 56 cents per share, in the fourth quarter from $130 million, or 23 cents per share, a year earlier.