Ethereum could collapse because it has no any limit in issue. Every year +18 000 000 ETH is added into circulation. So people will prefer to keep BTC or other altcoins will limited issue then ETH. it's my subjective opinion.
So if ethereum has not limit, then it is the same as ripple which doesn't have a limit too, and I think this coin can compete in the market. But fortunately, ethereum still has the highest price depends on ripple, so I think ethereum will stay behind bitcoin and ripple will behind ethereum. But every coin will get a new price after the market recover and who knows, the ethereum position will be change to another coin, we still don't know about this. But I don't think that ethereum will collapse.