Apple and Palantir shares slide in premarket trading following post-bell earnings

Apple and Palantir shares fell in premarket trading Tuesday after both announced earnings after the bell on Monday. The iPhone maker reported better-than-expected revenue in its fourth-quarter earnings, but fell short of estimates on iPad sales and issued a margin forecast that disappointed investors.Palantir beat Wall Street's third-quarter estimates, with U.S. commercial revenue topping government for the first time.Apple was last trading 4.4% lower, and Palantir was down 6% in premarket trading. Stock Chart IconStock chart iconApple and Palantir shares year-to-date.Apple's earningsApple's earnings were the first since John Ternus took over as CEO from Tim Cook in September. It comes as the company reckons with a global memory crunch and a scramble for computer components. The company said Monday that its memory costs were higher this quarter than in the June period. Despite that, Ternus said in a statement that Apple had just capped off its "best fiscal year ever." He told CNBC's MacKenzie Sigalos that Apple's growth came in spite of supply constraints and foreign exchange headwinds."The concern is profitability," said Violeta Todorova, senior research analyst at Leverage Shares...