One analyst suggested stocks may be suffering from "rally exhaustion."Shares of Palantir fell more than 8% after market open on Tuesday, leading a broader market decline after the software firm reported better-than-expected earnings, as some economists warned of “rally exhaustion” after a meteoric rise for several stocks this year.Palantir’s stock decreased 8.1% to around $190 shortly after trading opened Tuesday, pacing what would be the largest single-day drop for the stock since a 9.3% decline in August. ...