If you've got 4 years in, there's no good reason to stay post check-out unless you absolutely can't find something better.
However, the job hopper stigma can start to rape you in the ass if you have too many short jobs. Let's say that you take a new job and things are going well, but you're demoted at the 6-month mark. After you're demoted or passed over, there's really no good reason to put in high levels of effort. In an ideal world, people could just leave whenever that happened. In the real world, it can catch up with you.
If you don't have any short-term jobs, you can probably start looking, because one short job isn't that bad. If your last two jobs were under a year, you should probably phone it in, do the minimum for a while, and get a 2- or 3-year job on your CV before you move along.
If you've got 4 years in, there's no good reason to stay post check-out unless you absolutely can't find something better.
However, the job hopper stigma can start to rape you in the ass if you have too many short jobs. Let's say that you take a new job and things are going well, but you're demoted at the 6-month mark. After you're demoted or passed over, there's really no good reason to put in high levels of effort. In an ideal world, people could just leave whenever that happened. In the real world, it can catch up with you.
If you don't have any short-term jobs, you can probably start looking, because one short job isn't that bad. If your last two jobs were under a year, you should probably phone it in, do the minimum for a while, and get a 2- or 3-year job on your CV before you move along.