As I understand it bot trading is algorithmic computer trading, generally used by brokers/large traders who want to trade a large parcel of shares without impacting too severely on the market price. If they bought/sold the whole parcel at once the price would rise/fall a great amount.
I don't think it is ASX rules that limit $500 per trade but more that of online brokers (someone else may elucidate here).
If there are more bot trades buying then someone's looking to accumulate, if more bot trades are selling then someone's looking to offload.
