FINRA halted all OTC trading...OTC was having computer probems and quotes were not working so finra shut them down..the back up failed and they are working on it...straight from Charles Scwab. It is actually not a halt by FINRA, but the exchanges themselves actually having issues. Earlier they tried to move the trading to backup systems, but those failed as well...

11:33:44 AM : Stephen L.: Our last update was to expect the markets to be on and off for the rest of the day, as they try to work out whatever issues are causing the disruptions.