Do you think Bitcoin crash is an opportunity to enter the market?
Always is but in different market, bullish or bearish, you will have to exit shortly or hold for long term.
If it is a bearish market, buy dips and take profit when price bounces about 10% is good enough.
If it is a bullish market, buy dips and take profit around the latest peak or retest of temporary all time high.
It is always good opportunity to enter and only different on how long you let your buy position opens and how much you want to take profit.