Most investors will be glad to put this dismal week in the markets behind them. The S&P 500, which had been hovering around the 2030 mark to begin the week — and even saw an upward push for a time on Tuesday — has now slipped to levels just under 2000. As it is the beginning of earnings season, one might be obliged to think disappointing returns from big banks like JPMorgan ( JPM ) and Citigroup ( C ) have had a lot to do with this, but the surprise Swiss National Bank (SNB) decision to remove the Swiss franc from the euro, as well as a continually precipitous fall in oil prices, are having a larger effect […]