I will recemend you to buy only coins with good name in market and avoid shit coins, TRX, XRP, NEO, ETH, LTC, XMR are some projects with Trusted team and comunity in backup. Hope you will consider my advice.
Dump is the best time for buy but I more prefer with Eos and BNB, for me both have good foundation and will survive. Eos is similar with Eth, very idealist but have good progress in game platform. BNB is monopoly with Binance, they will try to not lost value and volume. I avoid popular coin because high risk high return, play in chaos like right now is not an option.