The ASX won't investigate. In fact they facilitate this by...

The ASX won't investigate. In fact they facilitate this by processing the opening auctions in batches and publishing the time when each batch is processed. That makes it easy for brokers to place or pull bids at the last second. They could (if they wanted to) minimise this kind of behaviour by just resolving the opening auction for each stock individually and ripping through the whole lot. That would take the predictability out of it.

In any case, it's a bit of a stretch to call it manipulation. It's no different to bidders on eBay going in with a killer bid in the last second or two.

If you're going to try for a stock in an auction, bid the best price you're prepared to pay (or take). If you get a better price then you're ahead, but you won't do worse than your limit.

I've learned not to go into the auctions... they're too much of a lottery.