Rough start to 2017 for Dow index plagued by downgrades By: CNBC.com News January 12, 2017 at 16:12 PM EST Nearly one-fifth of the Dow Jones industrial average has been downgraded since Jan 3. Read More >> Related Stocks: Coca-Cola Company Exxon Mobil Goldman Sachs Group McDonald's Corp Procter & Gamble Walt Disney