There are two basic things that need to be implemented when the market suddenly falls like yesterday to make a profit. First, the attitude must remain calm by thinking that it will recover. Second, take the opportunity to buy as many coins as possible, such as top 10 coins.
But how will you know that it is the lowest it can fall? your advise is only for those who can Invest and HODL with their coins.
the problem is what about those short term traders in which we knew the majority of people here?
you can buy now and wait for a while but what if the fall continues and make your investment even lower to more than half and suddenly you need the funds ? then you are a actual loser?
this advise is depend on what is your strategy and capacity .
Buying the dip is a strategy that can only be used by long term investors, if traders try to do something like that most likely will suffer heavy consequences because of it, after all as you say there is no way to know how deep a decrease in the price is actually going to be, so those buying expecting an immediate recovery are taking even more risk by doing something like this.
This is not a problem for investors as they can wait long enough in order for the price to return to the previous levels at which they bought and at least breakeven, so while buying the dip is a great strategy people need to use it in circumstances in which this strategy is beneficial for them and not in circumstances in which it is a terrible idea for them to implement it.