Catch up on today's top five analyst downgrades with this list compiled by The Fly: 1. Yelp (YELP) downgraded to Underweight from Equal Weight at Barclays and to Sector Perform from Outperform at RBC Capital. 2. AeroVironment (AVAV) downgraded to Market Perform from Outperform at William Blair. 3. BlackRock (BLK) downgraded to Hold from Buy at Deutsche Bank with analyst Brian Bedell saying with the shares approaching his price target, the analyst sees the risk/return as less compelling. 4. Willis Towers downgraded to Equal Weight from Overweight at Morgan Stanley with analyst Michael Phillips citing valuation. 5. Esperion (ESPR) downgraded to Neutral from Buy at Citi with analyst Joel Beatty saying approval around the February 21 FDA action date is now largely priced into the stock. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.