It will definitely go below $ 400 in the next few days, I think it will go down to 350 $ and start to go up again. That is a very good support area of ETH and it will not easily collapse, if you want to invest, wait and buy at that price.
If that so, I will prepare to buy more ethereum at that price, but before I do that, I will analyze more to see if the price will go down or will bounce up. Waiting for a while will help us analyze more and get a low price (if the price will go down for more). But if the price increase, then maybe we don't have to do anything except wait for another downtrend.