a very useful strategy, but I personally prefer investing coins that have good prospects for long-term investments such as ETH, BTC, BNB even though the price is very volatile.
Even if you prefer investing in coins with good future potential for long term purpose, the strategy proposed by OP should still suit you. There is no harm holding some stable coins waiting for a market dump to buy the dips. This entails quick profit, but requires a lot of patience. Hence it's easier said than done.