There's one thing holding back investors today.Carnival Corp. (CCL) (CUK 0.11%) stock has proven the naysayers wrong from a few years ago and has bounced back in a big way from 2022 lows. It's up roughly 216% over the past three years and has become a rare turnaround story. However, it's still 57% off its all-time highs set back in 2018 as it continues to repay its standing debt of $27 billion.Big news is expected at the end of the month that could help it get even closer to its previous highs. You might wa ...