AUD-USD has had a hard time over the 0.5300 level this week, the key now expected to be a break of 0.5290. Below there, light stops will likely kick in, and could shift sentiment enough to force the 0.5270/60 region, where heavier stops are said to be lurking. Unless the pair can take out the 0.5330/40 region, the pair may well be primed to take a tumble.