Hong Kong is set to open its markets to trade on Friday in the first time since a nationwide blackout struck in the wake of the North Korea nuclear crisis.
The central bank said on Tuesday that it had “reserved the right” to restrict trading on Hong Kong stock exchanges.
It said the move would be “appropriate to prevent the spread of the black market, and the spread to other markets”.
The move comes a day after the central bank announced a ban on foreign exchange trades and other financial transactions between the city and the mainland, but did not specify which sectors would be affected.
Hong Kong markets closed on Wednesday.