Catch up on today's top five analyst downgrades with this list compiled by The Fly: 1. Facebook (FB) downgraded to Hold from Buy at Needham with analyst Laura Martin citing three factors that she sees creating a "negative network effect," namely its strategic pivot toward privacy and encrypted messages, the growing risks of regulation and "horrific" events like those recently in New Zealand that hurt Facebook's brand and are difficult to block from the service at a 100% level. 2. Quest Diagnostics (DGX) downgraded to Neutral from Outperform at Credit Suisse. 3. Aramark (ARMK) downgraded to Neutral from Buy at Nomura Instinet with analyst Dan Dolev saying while the company's "significant scale" in North America should drive consistent 5%-plus organic growth, "execution mishaps and inability to win sufficient new business" resulted in just 2%-3% organic growth versus 7%-8% for main competitor Compass. 4. BioScrip (BIOS) downgraded to Equal Weight from Overweight at Stephens with analyst Dana Hambly saying the company "surprised the market" by announcing a merger with Option Care. 5. PVH Corp. (PVH) assumed with a Neutral from Buy at Citi with analyst Paul Lejuez saying while PVH has two brands with good global growth potential in Tommy Hilfiger and Calvin Klein, the company overall is still heavily dependent on the North America wholesale and outlet channels. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.