Edit: Small error in the chart, point B of the should be confluent with point C of the , leaving it at a fib level of 78.6
This is not a foolproof prediction of what's going to happen, rather one that is likely to happen.
If we all know where the market is headed, everyone would be rich, but this is a zero-sum game.
Historically, prices tend to follow harmonic patterns that may seem "random" to laymen, but the fact that many other investors use these for their entries and exits give those who can follow it a slight edge. This is not to be confused with whether investors have enough purchasing power to move currency pairs significantly, but you could always use that to your advantage on false breakouts of where the general population expects it to go, and do the opposite given the chance.