Palantir (PLTR) fell as much as 9% on Tuesday's trading session after Citron Research issued a short report calling the A.I. software company's valuation into question. It believes Palantir's stock should be worth no more than $40 as OpenAI's valuation inches toward $500 billion. Sam Vadas explains the pessimism behind Citron's report and discusses how A.I. changed perspectives on valuations across tech.