No trading floor, no problem. Citadel Securities execs lay out how they're launching billions in new shares into the market with a process adapted on the fly — including an IPO today.

· Citadel Securities has handled nine of the 10 initial public offerings held at the New York Stock Exchange since the temporary closure of the floor on March 23. 
· The group that handled the process, known as designated market makers, completely revamped its framework in order to do it entirely remotely. 
· Communication...