The medical lab operator Quest Diagnostics Inc (NYSE:DGX) was downgraded from buy to underperform by Bank of America Merrill Lynch on weak earnings outlook estimate for 2014. As a result, the price target was also lowered from $64 to $55 a share. Year-to-day compared to the S&P 500, Quest Diagnostics is vastly underperforming. For example, the S&P 500 is 25 percent year-to-day, while the Quest Diagnostics is barely above 1 percent. Bank of America Merrill Lynch also reduced its 2014 EPS estimate for the medical lab operator by 15 cents.