It's the right time to buy, i believe that ethereum together with the altcoins will make their peak on bull season, so if you have the funds you better fill your bags now. Whales manipulated the price today so they can stock more coins before it reaches the bull season.
Well the fact that it's nosediving means that it' a terrible time to sell. Eth for me is one of the steadier coins to invest on especially in the long term. So a drop like this can easily be an opportunity for any investor.