Use of financial derivatives exploded in Australian banking over the last six months.Combined assets and liabilities of financial derivatives soared to A$86 billion from an uncharacteristic low of $3 billion at the end of 2014.Portfolio investment took a tumble, from $50 billion to $118 billion over a quarter, so we may be playing a semantics game.The ABS report on Balance of Payments and International Investment Position, Australia, June 2015 is thus a corker.Whatever the cause, derivatives  - forms of financial protection choked into vulnerable formulas - are in vogue.