Catch up on today's top five analyst downgrades with this list compiled by The Fly: 1. Williams (WMB) downgraded to Market Perform from Outperform at Bernstein with analyst Jean Ann Salisbury saying as delays in LNG starts and surprising growth from the SW Marcellus/Utica and Haynesville she pulled her bearish gas thesis of half-cycle breakeven gas forward. 2. GlycoMimetics (GLYC) downgraded to Hold from Buy at Jefferies and SunTrust while being downgraded to Neutral from Overweight at Piper Jaffray. 3. Prudential (PRU) downgraded to Neutral from Buy at Citi with analyst Suneet Kamath saying he sees "muted" earnings growth for Prudential over at least the next year or so. 4. Mercer (MERC) downgraded to Sector Perform from Outperform at RBC Capital with analyst Paul Quinn citing its Q2 earnings miss. 5. CDW (CDW) downgraded to Underweight from Neutral at JPMorgan with analyst Paul Coster citing valuation. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.