Trading this basic strategy without filtering any of the signals can result in whipsaws. A whipsaw is when there is a crossover in one direction, followed shortly after by a crossover in the other direction. Whipsaws can result in a number of losing trades in a short period of time.
To help avoid this, only take +VI crossovers (above VI) when the overall trend is up.
When the overall trend is down, only take -VI crossovers (above +VI).
In either case, use a crossover in the opposite direction as an exit signal. A manual stop loss should also be placed to control risk. For a long trade, place a stop just below a recent swing low, and for a short trade place a stop just above a recent swing high.
Its Professionally used as a Confirmation tool, Not a Decision tool!
Should be used when you see a Breakout, to confirm whether it is a false breakout or not! :)