It's the 24th year running that the Economist magazine has published its famed Big Mac Index -- a tongue-and-cheek way of measuring the purchasing power parity (PPP) -- that is, the relative over and undervaluation of the world's currencies.

As investors, one of the most difficult things to do is to keep an open mind. Rather than let your feelings interfere with reality, you should avoid trying to have too strong an opinion on where the market may be headed and you should just let the facts on the ground (or in this case the trading floor) determine how you will manage your money.

Earlier today, President Obama signed into law the Dodd-Frank financial overhaul bill.