perfect bounce against resistance,
Why is it an indicator to sell when you see one? IMO it's one of many signs of the beginning of a bull market sort of like a tactical door breach where everyone is waiting for it to break to run inside.
To put it simply, that price zone was a major support during months, thus the market participants will mostly buy at that price. Since it has been broken downward, all people that bought at that price are now willing to sell when they can break even.
Now, ETC needs much more "fuel" to break that resistance. smart money, market participants are call it what ever you want, need to accumulate at lower points for that resistance to break.