Dow drops as oil market continues to crumble

As the oil market continues to crumble, U.S. stocks saw a second straight day of losses and stocks slid sharply around the world. In other countries, oil prices remain well above zero, but in the U.S., a day after oil futures plunged below zero for the first time, traders remain close to paying people to take it off their hands. NBC News’ David Gura explains how prices can go negative.April 21, 2020