Trading halts are common historically in many markets in the US as well, like you said. Commodities have a history of halts, and there have been many periods w

Trading halts are common historically in many markets in the US as well, like you said. Commodities have a history of halts, and there have been many periods where you'd have three or four days in a row of halted trading in the first minute; essentially these highly leveraged markets needed to move way, way down or up and took a while to do so with the halt system. I don't know what commodities markets in the US do now with respect to halts, but in a world where we have retail players swimming with very sophisticated traders, I think the halts likely help more than hurt for the small players; retail brokerage users have no hope of dealing with short term spikes and may get stop-lossed out unfavorably; a halt lets them think hard and change up their stops overnight or once they see the news.