All - I've used this trick a few times to my advantage so...

All - I've used this trick a few times to my advantage so passing it on in case others don't know.
The background is that I'd had a buy order in for most of today at 30c and at the closing auction it had not been filled. Let's say the total volume bid at 30c at the close was 160,620 (It wasn't but I cannot remember exactly what the figure was. Anyway I noticed that JMS was predicted to close at 30c but the excess shares bid was something close to 160,600. I.e all those who bid more would get their orders filled but would only pay 30c while those who bid 30c would largely miss out. In this situation there are often a couple of bids on both the buy and sell side which will quickly update to ensure that the close will be 30c. I guess they are using the setup to soak up as many shares as they can at 30c but not pushing it to 30.5 or higher.
To take advantage, I adjusted my bid to 30.5c. Then what happened is that the "bot" orders are quickly amended so that again the price does not go higher than 30c. It is quite fascinating to watch them. The upshot is that my order was filled at close at 30c. I guess the danger is that occasionally the bots will not be able to react fast enough and you may pay the extra 0.5c. DYOR and GLTAH