The ASX could have done a better job communicating with the market and with rival exchange operator Chi-X on the day of its outage, ASIC's findings indicate, leading the ASX to review its communications protocol.

The regulator's report into the September 19 outage confirms that market participants were confused on the day and relied on formal and informal sources of information about whether the exchange would trade normally. The ASX closed trading early after an unusual technical failure caused a delayed and incomplete open, and the cancellation of 3,062 transactions. Chi-X was still able to settle trades even though the ASX was down.