It went down today because it went up quite a bit yesterday. It is just a little correction and between yesterday it is still around .50 cents up. FB is not running with strength like it was a couple of months ago hence the choppy trading. I would not read too much into it other than this is the way it will trade for awhile.
It's Friday. That's the best response I have for "what gives." I'm sorry to say, I didn't buy any shares today. Had the limit @ $27.83. I think Monday's open FB will be back on the move up. May be forced to buy at $28 and change. The point is, it may have dropped today, even though it should have been up. But "up" is coming.