There can be no question that this is the most difficult environment I have seen in my 20 plus years in the markets. As I write this (Oct. 15), the market just closed with its largest one-day percentage loss since 1987. Stocks have been more volatile than ever before with multiple hundred-point moves the norm, while overall the trend remains firmly downward. The combination of the credit crisis, weak economy and hedge-fund deleveraging has investors far beyond worried. Money is being pulled out of mutual funds by the billions, and there are no buyers in sight.It is times like these that I try to focus on the basics of investing and allow Mr. Market to work for me instead of against me. I spent some time this week rereading the writings of Ben Graham to help me achieve this. One article I revisited is an interview Graham did in 1976 with the Medical Economist. In it, Graham outlined a simple approach for finding stocks that were cheap in price and offered a sufficient margin of safety. He simply bought stocks that had an earnings yield of twice the AAA bond rate and owned twice as much as they owed. At the time, he had 50 years of research showing this basic approach beat the market by a 2:1 margin. My own more limited research shows that it has done so for the past 20 years as well. I am, in principle, a bottoms-up stock picker. On occasion, however, there will be clusters of stocks that show up in screens, and I try to apply some macro thoughts to the group to see if I can figure out why so many similar companies are trading so cheaply. Sometimes, as in the case of financials last year, applying a macro picture will keep me away from the stocks. When I ran the Graham screen, however, I saw a group of stocks that have an incredibly strong positive outlook based on the big picture.