Ues, it is old and best strategy for both trading and investing and in fact, it works on every trading material and this is how the market is been moved. But you need to be very careful in nowadays as there are possibility of this strategy to fail in coming months because this strategy is been old for now and almost all people use it for trading and so in coming months and years you will see the market dynamics changing a lot and at that time you need to change or tweak the strategy.