FINRA (non-governmental organization)can halt trading on short notice especially when a publicly traded company is going to release significant news about itself. This seems like very significant news. The SEC has the authority to suspend the trading of a security at any time it pleases and usually when a company screws up. The government accidentally pre-released DRL bankruptcy filing before the bell before the press release. (It was supposed to be posted the next day.) Once they realized the mistake they quickly suspended trading for the rest of the day.
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