Stocks fell as the Fed said its top officials mostly agree its massive bond-buying program should wind down. The Dow fell a sixth straight day, its longest losing streak since July 2012. The index is off 4.9% since its Aug. 2 record high. In July’s minutes, Fed members said it ‘‘might soon be time’’ to slow bond purchases, which since 2008 have kept interest rates low, encouraged growth, and — some traders say — inflated stocks. Retailers again were in focus: Target fell as it gave a muted sales outlook for the rest of the year. Staples and American Eagle also sank. One bright spot: Lowe’s beat profit expectations and raised its full-year forecasts.