Very True if you are buying a Blue Chip (Just like in Stocks i.e. Exxon / Mobil during Oil market Crashes)
If you ask how to buy the coin at the right time, the answer will be difficult because we do not know when the price touches the bottom and then bounce up. But as long as you can buy at a lower price, even if the price is still down, you will have a chance to make a profit because the price will bounce up. That is work for the coin that has an opportunity to increase such ethereum, bnb, and the other top coins. But if that is about the other coins that do not have much support or low market cap, it will not be easy to detect the lower price.
Maybe I will try to buy the coin when the price drops deeper and once the red candle shows in the market, I will prepare to wait for the next candle or place my order buy at another lower price. But I will analyze to predict when the price reaches the lower price or trying to detect if the downtrend is come or still waiting for more.