Next difficulty retarget occurs at block 526175.0 (eta 10.8 days): 5.17423501215e+12 / +20.1% [est.]
Wtf? 20% increase?
Which means 20% less profits.
I think the last diff increase was just yesterday, might have been a bunch of quick lucky blocks or something.
Wait a few days and you'll see it level out a bit, as the network hashrate doesn't appear to have jumped drastically.
On the other hand a 20% increase is not unheard of there have been a few of those since I started mining last year.
Indeed it's caused by web sites that have no understanding of statistics.
The difficulty re-target is based on 2015 (of the last 2016) blocks each 2016 blocks (which is about 2 weeks)
If they calculate it based on 200 blocks then they are only using a tenth of the data used to determine the diff change.
So the estimate will be pretty meaningless.
Even 2015 blocks is not a very accurate estimate of the Bitcoin network hash rate, but alas it can't be a lot more due to the risk of having a very slow network difficulty change if the global hash rate drops a lot.
Anyway, it's best to ignore the diff estimate sites until close to the next diff change.
They're attempts at estimation is often brain dead
