Just a fortnight ago, a Whale saw an opportunity in the ETH dip and decide to buy over a 100k ETH and stake them all at $4.1k; another sold his BTC and opened a long position for ETH on an exchange. Then suddenly the floodgates opened and more Whales began "dumping" to buy more ETH. Any obvious reason for the flow of liquidity into ETH? Be my guess!
While others were busy analysing the market, these guys acted promptly. Put that into perspective now; ETH has since reach a new ATH since then and hasn't returned to that "bottom" after those moves.
There is no alternative to analysis in the crypto world. Jumping into an investment immediately after seeing a market movement without analysis is as risky as gambling. Sometimes, if you are lucky, immediate action without analysis can bring a good profit, but it will be much more risky. ETH and Bitcoin are very strong coins and their prices increase gradually, so it does not mean that their prices cannot fall. Sometimes, their prices can see very large downtrends. Futures trading is a very risky place, if you jump in panic here, you may have to face large losses very quickly.