The price per coin in Euro or Dollar is influenced by what Bitcoin does. When you have invested in a coin like Ethereum (or whatever coin transfers back to Bitcoin) it is important to look at how many Bitcoin (usually exchanges show worth in Satoshi (=0.00000001 bitcoin)) it is worth. You could even lose money by just looking at the prices in Euro/Dollar.
Ethereum:
Bitcoin:
Looking at the Ethereum chart, in blue is Dollar and the green line is price in Bitcoin. Compare the green Bitcoin line in the Ethereum chart with the Bitcoin chart below. This learns us that when Bitcoin price per coin is high, Ethereum return per coin in Bitcoin is low. So although it may look like it is worth more in Euro/Dollar, it is actually not if you have already sold your Bitcoin for Ethereum.
You say it is still €50 less than what it was this morning, but we also see that Bitcoin itself was around $1000 more per coin this morning.
Ideally you want to sell your Ethereum when Bitcoin is at its lowest and buy Ethereum when Bitcoin is at its highest. A Bitcoin crash for example could be very good for business when you have invested all your Bitcoin in altcoins, very much when your altcoin is not influenced at that very moment by the crash. The return in Bitcoin is much higher and then you just have to wait for the Bitcoin to recover and buy altcoins at their lowest (lowest possible).