I don't disagree the possibility of an Iceberg, but that you or...

I don't disagree the possibility of an Iceberg, but that you or Mixed Bag are seeing that volume, could easily be a glitch with your third party systems - not sure which broker you are using. Not showing on mine - and I pay for a standard of real time data.

Iceberg orders have been around since 2010 on the ASX. The electronic algortihtms and professionals of the vested big mkt participants would be screaming blue murder on the ASX if their Iceberg orders visiable on a pre-open balance - the ability would not be restricted to OCC - as fheir ability to get filled on large orders made far more difficult.

Sorry, but I have to disagree your experience with your platform as a probable red-herring.