The signals have to be personal because if they had to do with metrics (that were good), you wouldn't have this problem. In my opinion, it's when either/most/all of these are true:

- you don't feel you are capable (or want to) fix growth

- you don't see any hope - ie you picked the wrong problem and there's no p/m fit

- you are not hustling enough to fix the problems and you don't know why (prob because you lost passion or steam)

1. No growth. If you're struggling to grow more than 30%/month it might be time to stop or sell.

2. You hate it. I had a decent growing startup, but I hated the user base. It was a keto diet app. The users were people who lost lots of weight on keto, decided that nutritionists were liars, and were relentlessly anti-scientific. We sold it, and the guys who bought it hated it too.

I hated building apps for politicians, many were like mobsters, and it was a terrible feeling helping them. I once quit one partnership because my partner would just lie, break promises, overhaggle with everyone, and the people we were working with would do the same with us (me).

There was one partnership I ended because the other guy refused to fire some people. They weren't just underperforming, they were unreliable and promising things, then acting like the conversation never happened. But this is really common when you can't pay market rate.

But it's like quitting a job. If you dread coming in to work every day, maybe you should be doing something else. Startup DNA is vital. Can't build a billion dollar company when all your energy goes into rent negotiations.

Same way you decide when to resign in a chess or go game. When you know you are going to lose with certainty, or you are hopeless.