"For the 24th year running that the Economist magazine has published its famed Big Mac Index; this index is a tongue-and-cheek way of measuring the purchasing power parity (PPP) -- that is, the relative overvaluation and undervaluation of the world's currencies," notes Nicholas Vardy.

The editor of The Global Stock Investor explains, "What does the Big Mac now say about the relative value of global currencies?

"According to the theory of purchasing power parity, a dollar should buy the same amount of the same good across all countries. By comparing the cost of Big Macs -- a good that is produced in about 120 countries -- the Big Mac Index calculates the exchange rate (the Big Mac PPP) that would result in hamburgers costing the same in America as they do abroad.

In the wake of the incredible volatility of recent days, we turn to several leading financial newsletter advisors, asking "Where's the market going from here?"

Here's an updated assessment -- as well as some select investment ideas -- from Elliott Gue, Richard Moroney, Nicholas Vardy, Keith Fitz-Gerald and Mike Cintolo.

We begin with Elliott Gue, editor of The Energy Strategist, who asserts, "Don't panic. Selling into a panic-driven market is one of the worst and most costly mistakes you can make as an investor. I do not believe the fundamentals justify the downside in my recommended stocks, nor do I see this ballooning into an outright crash or collapse.