On Wednesday the S&P 500 went up 30 points in anticipation of a Remain vote outcome. Which is pretty stupid. A Remain success meant that nothing changes. So the market went up 30 points on the great investment logic that nothing changes.
As I write at 8:50 am PT, the S&P is down 56 points. Subtract 30 from that and the market is down about 26 points from Wednesday. Which is 1.2% which is not that big of a down day any longer. Or an up day.