The ADRs are certainly not very liquid. It's not so hard to buy...

The ADRs are certainly not very liquid. It's not so hard to buy shares, although you may have to pay a bit more to get a large amount. The bigger problem is selling. At times, the daily volume has dropped under 1000. To sell even 10 thousand ADRs would take a long time, especially if you wanted anywhere near a reasonable price. Right now Starpharma is almost completely unknown outside of Australia. I think this will change in the coming years and volume will increase. That said, I believe most investors have never bought an ADR of any stock.

As far as price action between the two markets goes, one usually follows the other fairly closely. When TOO called US results "lacklustre" I think he/she was probably looking forward to the next trading day. A 1% difference signals a possible 1% further increase in Australia on the next trading day. I suppose that would be lacklustre, but after a 15% pop I'm okay with that. When added to my most recent purchase LAST MONTH it comes to 46.89%! I, for one, can not even think to complain about a few flat or down days along the way.