When the market falls it is best to buy coins that go to the top 100. However, I advise you to analyze each and follow the news, because after the fall, not all coins rise. There is fierce competition in this market.
Thats right, when the price goes down you can't randomly choose a coin even though it's from the top 100, because there are some coins that can't be recovered. do a deep analysis where coins that still have the potential to rise again and the price has stopped to down, buy that!