RE: RE: RE: Halt hmm? The Investment Industry Regulatory Organization of Securities Trading can make the decision to impose a temporary suspension of trading in a security of a publicly listed company, usually in anticipation of a major announcement from the company. Trading halts are issued based on the principle that all investors should have the same timely access to important information about the companies in which they invest. IIROC is the national self-regulatory organization which oversees all investment dealers and trading activity on all stock markets and debt markets in Canada .