Here´s a simple monthly chart of the S&P500.
You can see how efficient it has been in following the general market trend. Although it has had some minor whipsaws, you can see the it has also served well in working as re-test area for counter-trend moves.
However, it is important to emphasize that this is a monthly chart so watching it on a daily basis will not have a significant effect. As of this month (there´s still 2 trading weeks in the month left), I will start posting this chart on a monthly/2 week basis, depending on market conditions.