Catch up on today's top analyst downgrades with this list compiled by The Fly: 1. Ambarella (AMBA) was downgraded to Hold from Buy at Craig-Hallum and to Neutral from Buy at Roth Capital. 2. America First Multifamily Investors (ATAX) downgraded to Perform at Oppenheimer with analyst Ben Chittenden saying Hurricane Harvey likely reduces the value of the company's Houston properties. Further, the analyst views the shares as fully priced. 3. Greif (GEF) downgraded to Neutral from Buy at BofA/Merrill with analyst George Staphos citing valuation and reduced catalysts. 4. Rice Energy (RICE) downgraded to Hold from Buy at US Capital Advisors. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.