No one knows if this is the start of a new bear market or just another bear trap on the way to higher highs. Everyone invested should have a sell or buy plan that they setup in advance and follow that plan. This helps you remove the effect of emotion in your buy/sell decisions.

No one can time the market perfectly and being pissed about not selling at $4999 is not realistic. What if you sold at $4999 and the next day it went to $5500... would you still be upset?

Have a plan and be disciplined.