Not sure on the exact why, but a thought on the overall market dynamics currently happening.

There clearly is more demand to send the price up this much this quickly, but more importantly to me is that demand wasn't met instantly with massive amount of selling pressure as it has been for months on end here.

With the reduction in costs for running full nodes there are multiple witnesses that need to sell less to cover their bills (including STINC). STINC lowered their overhead drastically (fired dead weight) due to an instant need to cut costs. Maybe they are more on solid ground with lowered overhead in terms of labor and server costs. STINC also now has ad revenue kicking in meaning even less need to sell STEEM.

At the very least those who need to pay bills with the sale of STEEM need to sell less each day as the price is rising meaning less and less selling pressure. The death spiral that seemed to be happening of the lower the price the more that had to be sold by large accounts that rely on STEEM to pay the bills which then caused the price even lower thus needing to sell even more just might have been broken. We will need to see the gains hold to know for sure. But even at these prices it would take about 50% of the STEEM to pay the same bills vs the lows. If we get to the 60c range it's 1/3 vs the lows. At that point I will be a lot more comfortable with the selling needs of the dapps and Steemit Inc not causing us to go straight down to 0.

Add in the printing of SBD again which means those treating steemit like an ATM are now dumping SBD daily, not steem. I haven't seen numbers of this, but guessing the number is fairly large in terms of consistent selling pressure from these people who's only purpose is short term gains.