Twitter IPO at the NYSE (9 images)

Guests of Twitter look at a camera before ringing the opening bell while waiting for shares of Twitter to be traded for the first time at the Twitter IPO on the floor of the New York Stock Exchange on Wall Street In New York City on November 7, 2013. The NYSE Euronext staged a first-ever weekend test for the initial public offer two weeks ago to avoid reprising the problems with rival Nasdaq's systems that delayed timely orders and ruined Facebook's debut on Wall Street. UPI/John Angelillo

Twitter co-founder Jack Dorsey, Twitter co-founder Biz Stone, Twitter co-founder Evan Williams and Twitter CEO Dick Costolo stand on the floor of the NYSE after shares of Twitter are traded for the first time at the New York Stock Exchange on Wall Street In New York City on November 7, 2013. The NYSE Euronext staged a first-ever weekend test for the initial public offer two weeks ago to avoid reprising the problems with rival Nasdaq's systems that delayed timely orders and ruined Facebook's debut on Wall Street. UPI/John Angelillo

Twitter CEO Dick Costolo, Twitter co-founder Jack Dorsey, Twitter co-founder Evan Williams and Twitter co-founder Biz Stone react at the ringing of the opening bell before shares of Twitter are traded for the first time at the New York Stock Exchange on Wall Street In New York City on November 7, 2013. The NYSE Euronext staged a first-ever weekend test for the initial public offer two weeks ago to avoid reprising the problems with rival Nasdaq's systems that delayed timely orders and ruined Facebook's debut on Wall Street. UPI/John Angelillo

Traders wait for shares of Twitter to be traded for the first time at the Twitter IPO on the floor of the New York Stock Exchange on Wall Street In New York City on November 7, 2013. The NYSE Euronext staged a first-ever weekend test for the initial public offer two weeks ago to avoid reprising the problems with rival Nasdaq's systems that delayed timely orders and ruined Facebook's debut on Wall Street. UPI/John Angelillo