Apple and Amazon results pose tech rally's toughest hurdle yet

Results from Apple Inc. and Amazon.com Inc. after Thursday's close represent the next big hurdle for the market's tech-fueled rally, and it may be the hardest to clear. Most Read from Bloomberg Both stocks have been critical to the S&P 500's advance this year, attracting investors with their relatively durable revenue streams and market dominance. But whether they can fuel further gains is in question, given they trade at lofty multiples, face headwinds in their core businesses, and have limited direct exposure to artificial intelligence — a key driver behind this year's jump. "At these valuations, multiples either need to…