The upward-sloping triangle pattern on the Aussie chart graphically illustrates the conflict between supply and demand for the currency.
The pattern is formed with a horizontal resistance level, which can considered as a measure of supply. Price fails to move above this resistance line as the supply of sellers overwhelms the demand from buyers.
The second part of the pattern is an upsloping trend line, which shows the changing levels of demand. The line slopes upward because buyers enter the market more aggressively to take positions as the price falls and, worried about missing out, they bid higher to get a position.
The result of these two influences is an upsloping trend line. In equity markets this is a powerful measure of crowd psychology. It has the same function in currency markets, but not quite a powerfully because many currency traders are forced to take the opposite side of their clients' transactions, irrespective of their view of the market direction.
However the pattern remains a strong predictor of upside breakouts. The depth of the base of the triangle is measured and this valu projected upwards above the resistance line to set an upside target. Again, this method is reliable with equities, but applied with caution in FX markets.