2016 Guidance Affirmed, page-90

Trading patterns now may be influenced by EOFY book balancing.
If you have some capital gains you can avoid tax on gains by selling a loser (like EPW is in most portfolios now).
Then, if you like it, grab it back later - even if you buy back at a few pips more you are still better off by far.
It's called a wash trade and if the purpose is to avoid tax then not allowed , but if you are a broker with multiple account and gazillions of shares who's going to notice and who's to say one client didn't say SELL and another BUY.
If you are a little guy though the ATO will probably throw you under a bus for it
.