On The Fly: Top five analyst downgrades

Catch up on today's top five analyst downgrades with this list compiled by The Fly: 1. Proofpoint (PFPT) downgraded to Sell from Neutral at Goldman with analyst Gabriela Borges saying Proofpoint screens as one of the most expensive stocks in Software, while the Street is overestimating the sustainability of the company's growth. She expects moderating share gains in email security. 2. Ultragenyx (RARE) downgraded to Neutral from Overweight at Piper Jaffray with analyst Steven Breazzano citing the company's report that the Phase 2 triheptanoin study in Glut1DS patients with seizures missed the primary endpoint of overall seizure reduction. 3. Altria Group (MO) downgraded to Underperform from Sector Perform at RBC Capital with analyst Nik Modi citing valuation and the belief that the company probably won't be acquired. 4. Nimble Storage (NMBL) downgraded to Hold from Buy at Maxim with analyst Nehal Chokshi saying regulatory filings make it clear that Hewlett Packard Enterprise (HPE) was able to negotiate an effective "no shop" clause in its deal to acquire Nimble Storage (NMBL) for $12.50 per share in cash. The analyst, citing the "clear evidence" that Nimble is not in play, downgraded the stock to Hold and lowered his price target from $14 to the $12.50 deal price. 5. Norfolk Southern (NSC) downgraded to Underperform from Sector Perform at RBC Capital. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.