When market is falling there are 3 tactics I use, First is to sell high and buy low to increase my holdings (works 50% of the time) if it doesn't work I usually switch to other coins and never come back to the one I sold if it is not lower than my selling point, Second is I cost average my holding by buying the dip of the dip of the dip and trying to be patient for it to recover but this needs research and confidence in a coin so you can hold it and buy some more, third is plainly holding and riding the wave. It depends on the scenario which tactics I use.