Thats the common thing with cryptocurrency. Whenever the market turns bearish it is good to invest as much possible. For this what you need to do is watch the market and find the right point to sell and buy it back. At some instance we might miss the selling at the peak and if you find the market is turning bearish go sell it to record some profit through buyback than holding it.
"Buy low and sell high"
That's the strategy that we've been hearing and saying whenever someone asks for an advice. Yet, many still don't do what we say to buy during the market crash.
They don't follow such advice because they think that there's more for it than to listen to that common advice.