Don't worry, you are not alone: as Bloomberg's macro commentator and former FX trader, Richard Breslow writes, "all I heard yesterday morning was, "What the hell is going on with equities?"
In light of recent reports that pension funds - such as Norway's, the world's largest - and various sovereign wealth funds are becoming increasingly activist in stocks, in many cases with leverage, not to mention central banks such as the SNB which keeps buying and the BOJ which holds 75% of Japanese ETFs, the simple answer is staring everyone in the face.
Here is Breslow's explanation:
Stocks Are Rallying for a Very Simple Reason
All I heard yesterday morning was, "What the hell is going on with equities?" They were of course looking like they had become untethered from reality and wanted to simply go to infinity and beyond. Then, at day's end, I kept being asked, "What the hell is going on with equities?" They had, by then, come down to Earth. At least for an afternoon.