Catch up on today's top five analyst downgrades with this list compiled by The Fly: 1. Costco (COST) downgraded to Underperform from Market Perform at Bernstein with analyst Brandon Fletcher saying "membership exhaustion" poses risks to the company's U.S. and international growth. 2. Bandwidth (BAND) downgraded to Underweight from Equal Weight at Morgan Stanley with analyst Meta Marshall saying the company is a good play on the growth of next-generation communications but its relative valuation versus peers "gives too much credit for platform depth." 3. Akamai (AKAM) downgraded to Sector Weight from Overweight at KeyBanc with analyst Brandon Nispel saying the downgrade is based on his view that accelerating growth for CDN in 2020 is built into expectations and the stock's valuation. 4. Hilton Grand Vacations (HGV) downgraded to Neutral from Buy at Goldman Sachs with analyst Stephen Grambling saying while leveraged buyout internal rate of returns could be attractive to $40 per share or higher, other names in the Lodging space offer better risk-adjusted returns. 5. U.S. Steel (X) downgraded to Underperform from Outperform at Macquarie with analyst David Lipschitz saying he expects steel prices to stay weak and the company's cash flow to be under pressure in a weak pricing environment. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.