Catch up on today's top five analyst downgrades with this list compiled by The Fly: 1. Alaska Air (ALK) downgraded to Neutral from Buy at UBS with analyst Darryl Genovesi saying he believes consensus estimates are too high and in particular reflect too rosy a RASM view given progressively more intense competition in its network. 2. Patterson Companies (PDCO) downgraded to Underweight from Neutral at JPMorgan with analyst Michael Minchak saying the company faces more near-term headwinds and uncertainties relative to other names he covers. He believes it will take time for Patterson's initiatives to bear fruit. 3. Cemex (CX) downgraded to Sell from Buy at UBS with analyst Mauricio Serna says he expects the share selloff to continue given the company's "struggling" international operations and "still high" debt. 4. Atara Biotherapeutics (ATRA) downgraded to Sell from Neutral at Citi with analyst Yigal Nochomovitz saying the recent 200%-plus rally in the shares is not supported by fundamentals. 5. Tanger Factory (SKT) downgraded to Underperform from In Line at Evercore ISI. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.