Piper Jaffray analyst Andrew Nowinski raised his price target for Proofpoint to $140 from $136 saying the company reported "solid" Q1 results, beating the high-end of revenue and billings guidance. . However, the stock traded down 6%, likely due to a reduction in the fiscal 2019 earnings guidance due to a new tax law and Q2 billings guidance that was modestly below consensus, Nowinski tells investors in a post-earnings research note. The analyst, however, believes the prior consensus billings estimate for Q2 was "mis-modeled by many on the sell-side and was higher than management's original guidance." As such, he does not view the new Q2 guidance as a guide down and says it "was actually a raise." He reiterates an Overweight rating on Proofpoint.