Stocks turn down at lunchtime, the Dow (DIA -0.3%), S&P 500 (SPY -0.2%), and Nasdaq 100 (QQQ -0.4%) all at session lows as some may be trimming positions ahead of what should be a vital employment report tomorrow morning. Long-term Treasury prices (TLT +0.4%) move to their highest levels in about 2 weeks.