Catch up on today's top five analyst downgrades with this list compiled by The Fly: 1. D.R. Horton (DHI) downgraded to Market Perform from Outperform at Keefe Bruyette. 2. Ball Corp. (BLL) and Silgan Holdings (SLGN) were downgraded to Underweight from Sector Weight at KeyBanc. 3. Ciena (CIEN) downgraded to Neutral from Overweight at Piper Jaffray with analyst Troy Jensen saying he sees 2018 being a more challenging year for the company. 4. Sigma Designs (SIGM) was downgraded to Hold from Buy at Lake Street, Benchmark, and Craig-Hallum. 5. HollyFrontier (HFC) downgraded to Underperform from Neutral at BofA/Merrill with analyst Doug Leggate citing full 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.