Of course, everyone is monitoring major indexes. In stock2own we love to have more than just one view at the same thing. Therefore we are adding not so commonly used indicators of the market health. And the idea of using them is simple: if you see all indicators agree with each other – perfect; if not - be cautious. As Mr. Weinstein said,
After a rally to a new high in the DJI, and the advance-decline line or another marked average refuses to confirm by also moving to a new high, that non-confirmation is a negative divergence. It is a reason to become defensive.Stan Weinstein's Secrets For Profiting in Bull and Bear Markets by Stan Weinstein
So, check it out and see if all indicators are in agreement with each other or it is time to "become defensive" or read more.