Palantir is a fast grower, and profitable -- but does it cost too much?Palantir (PLTR +2.95%) investors had a horrible November, as shares of the tech wunderkind tumbled 23% from an all-time high hit early in the month to a low below $155 less than three weeks later.Then Palantir bounced.By month's end, shares of the government contractor and artificial intelligence superstar stock regained 8% of its losses. As the calendar flips to December, Palantir's run isn't done. Shares rose 3.2% through 10:40 a.m. ET ...