Ethereum rolled back the transactions. The result ? Two coins, a split community and multiples of the actual loss wiped off the market cap instantly.
that is not the only result, it is not even the most important one either. losing market cap, price ,... don't matter at all.
the only important thing that happened to ethereum when they rolled back was that it lost its immutability and is no longer a trusted blockchain because the first thing about a blockchain is that it can not and should not change. if the "owners" decide they want to roll back they can do that any time they want specially when they switch to PoS and increase their power.