On Wednesday, July 8 the NYSE halted trading from 11:26am to 3:10pm EDT. All NYSE listed equities continued to trade on other venues. On any trading day there are a number of exchanges/markets where securities trade. In this instance even NYSE’s own Arca exchange continued to trade. The issue was due to a software upgrade made on Tuesday night, July 7, which was not performing up to expectations. These software issues have happened in the past and unfortunately will happen in the future. The main takeaway is our markets, both equity and fixed income, have many redundant places to trade the same securities. The United States is one of the most efficient, liquid, transparent, and safest places to purchase and sell equities and bonds.
It is like calling one of your favorite restaurants to make a reservation and find they are closed for a short vacation. This is an inconvenience, but you make another reservation and still have a pleasant dining experience.