Well I can't explain the next diff jump. I mean every ASIC on the market ROIs very very hard. Even S1. So who keeps adding power?
Might be ASIC companies that couldn't sell their gear like Spoondolies. Maybe even Black Arrow started mining with their X3. Some S2 were sold, some S1 and some SP-10 but they don't account for the upcoming 14-18% jump.
When you're a huge mining operation - and there are hundreds of these operations now, and you have committed millions to an operation that is in effect, depreciating every 12 - 14 days, you do not have much other choice but to expand with every spare cryptocoin you have left - and hope every other player eventually gives in or you yourself will go to the wall.
Mining operations big or small are probably attempting to expand their operations by 15% every 2 weeks to keep up with the rising difficulty, thus leading to a further 15% rise...
Doesn't take a crystal ball worker to figure this one out, we've already seen this happen in every other arena of supply / demand.
Hashrates will continue to rise and rise...its a case of who blinks first...usual case, biggest bankrolled operations will win.