We can buy anytime and I believe in the power of bitcoin. It is a great investment in all time but we have to choose some special time also to get higher level of profit. At the time of panic sell, we need to buy more crypto.
Buy more crypto, but 95% on market are only shitcoin. Investing in bitcoin is the best investment ever, you can read how Michael Saylor described investing in BTC is the best investment ever since the ROI in BTC is far higher than GOLD. Buy and HODL is the best way
Buying and holding is a good strategy if you are not greedy enough to wait for a huge price. Those who are saying that they made a high ROI on bitcoin are those people who invested early, for the price of bitcoin now, a 1000% increase is unlikely in a short period of time, but for altcoins, a 10,000% increase is possible in the bull run.
You don't need to be early now, you can still invest as long as it's in bitcoin because this is the best investment with holders in the long term with the ROI that you will get, of course, it won't be as big as the initial investment.
In actual altcoins I am still a little doubtful even though this could be a double ROI but still the decline will be more severe and difficult to recover.
So the only way is in bitcoin which is widely recommended, especially in some books that suggest it.