This means all of the rest of the parlay is useless. You have an offer to walk away with $600. Here’s where rational thought needs to come in play. (But oh man, just one more win and I could almost double it!!) Now your site (FanDuel typically) is giving you an offer - $600 to cash out now.
Your $10 parlay is just ONE SUNDAY NIGHT WIN away from $1000. In the afternoon, you hit on all of the first five! You’re excited. Numbers are made up, but here’s an Example: you put up a six team NFL parlay. There’s only one rational way to look at these.