Day Trader’s Aftermarket Lounge 17 Sep 2019, page-23

Yeah that was a bad input. Midpoint volumes can be seen by everybody cause they already happened. EOD data or even intraday.

What I really meant was depth which was the original question.
If no-one can see it it can't be traded ergo the brokers have to be able to see it.

There has to be a buyer to match the seller or it just can't work.

With no disrespect if you want more info check out ASX Centre Point info.

https://www.asx.com.au/services/trading-services/asx-centre-point.htm