You see o.5c because commsec etc. lower the quoted price with...

You see o.5c because commsec etc. lower the quoted price with cxxt trades which is contrary to accepted commercial practice. What it does is influence those who are not aware of it. It is generally regarded as poor practice as it can affect the run of the sp for retail traders especially. It is often criticised but nothing will ever be done about it so long as the big end of town controls the ASX.