Just a few months ago, it seemed like every piece of good news pushed Palantir Technologies (PLTR +10.32%) stock lower. After another blockbuster earnings report, Palantir stock surged rather than sank. Still, that doesn't mean the stock is cheapThe improving sentiment doesn't eliminate the biggest risk, that Palantir still commands a premium valuation as investors expect years of exceptional growth. In other words, the central debate on Palantir's stock is not whether Palantir has a great business. So, is the worst finally over for Palantir stock?