The market had factored in both their expectation of the chances of brexit and the uncertainty. The steep rise beforehand was because they'd calculated the former wrong, so the one-day fall can be ignored. Some of the uncertainly has gone with the result, but more remains. I reckon the market is 10% down on where it would be with a Remain decision, which is probably a fair assessment of the reduced value of the equity. The FTSE 100 has lots of foreign derived income, which of course has now risen, the FTSE 250 index is a better assessment of UK based companies, and that has fallen more.