One can go nuts trying to go through the vigors of "is it safe" type valuation measurements..... But what you really know.....is that the current events are extraordinarily negative...ie...like the perfect negative financial storm....the odds of seeing again being very small..... What you do know is that prices across the world have declined sharply ....and that people are very fearful..... One must have a lot of confidence in buying fear.....and one must know that nobody is going to raise a green flag to signal buy or sell..... One wants to know that the business is going to be around....whereby indices lend ease to this decision....