Catch up on today's top five analyst downgrades with this list compiled by The Fly: 1. Royal Dutch Shell (RDS.A, RDS.B) downgraded to Sell from Hold at Canaccord with the firm citing the gap between the average free cash flow generation of Shell over the past two decades and the medium-term target. 2. bluebird bio (BLUE) downgraded to Sell from Hold at Cantor with analyst Elemer Piros saying he sees a lack of catalysts as he does not expect data to be announced at this year's American Society of Hematology conference to de-risk the hemoglobinopathy programs. 3. Fluor (FLR) downgraded to Neutral from Accumulate at Seaport Global with analyst Ryan Cassil citing persistently weaker global macroeconomic trends and expectations for a continuation of weaker project activity in 2017. 4. Boston Beer (SAM) downgraded to Hold from Buy at Berenberg. 5. Estee Lauder (EL) downgraded to Neutral from Overweight at Piper Jaffray after the firm's semi-annual proprietary "Taking Stock With Teens" survey. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.