This is the question being asked fervently whether Stock market is going to be open on Columbus days.
Is the stock market open tomorrow (Columbus Day). Several banks are closed and there’s no mail delivery?
To answer your question, yes stock market is open on Columbus day.
However keep in mind that bond market will be closed.
My friend had this to say. The stock market is certainly open for Columbus Day, but Columbus Day is also a non-settlement day, because of the fact that, as you mentioned, it is a bank holiday. In other words, stocks that have been traded in the days before Columbus Day take an extra day to settle-but stocks traded on Columbus Day still settle in three days time-so Friday and tomorrow are considered the same for settlement purposes. There is some good information here at the NASDAQ site, it discusses different holidays and the policies for each: