Why the stock could have more upside ahead.Share prices of Carnival (CCL 0.59%) propelled higher this week after the cruise ship operator reported strong quarterly results and raised its full-year guidance. Despite the jump following its earnings report release on Tuesday, the stock is about where it was when it started the year.Let's look at the company's most recent results and whether it is too late to buy Carnival stock after its most recent upward move.Carnival posted strong results and increased guida ...