After yesterday’s sharp 3% drop in the stock market, the S&P 500 is in the red on a year-over-year basis for the first time nearly two years. Just barely, but it’s a minor milestone just the same. As of September 22, the S&P is off fractionally, slipping by roughly 0.4% vs. a year ago on a price basis. Should we be worried? Of course. No one needs another excuse these days, but we’ve got another one to add to the list.