Another sign is when your exit target has been reached. If you had a target to sell at $50,000, you should sell and not allow other to convince you. Many people will always be saying Bitcoin will continue rising but Bitcoin takes a break after rising for sometime and I think we're around that period that Bitcoin will experience a correction therefore my advice isn't for holders but traders.
I totally agree with this.
Sometimes you start an investment and you say to yourself that you'll sell at a certain price. By your calculations, you will make a certain percentage of profit by then because you plan to use the money for something maybe. Then when the time finally comes and the price of Bitcoin is around the range you wanted, you might get greedy or enticed by the upward slope of the price, and before you know it, the price has started going down and it might even go lower than your initial target.
I know that this can work both ways, it can work in your favor or against you, but if you have set a target and you want to use the money for something, that's feel you should stick to your initial plan even if the price keeps rising.