There is a lot of momentum with this stock, but that doesn't necessarily mean it is a buy.It's been a good year for investors in Palantir Technologies (PLTR 1.32%). The defense contractor that focuses on software and artificial intelligence (AI) is up over 100% year to date and now has a market capitalization of $80 billion.Revenue is accelerating, and the company is starting to generate positive earnings and free cash flow. Investors are getting bullish on the company's push to acquire commercial customers ...