Stifel analyst John Marchetti said Ciena delivered strong Q3 revenues with meaningful margin and EPS upside. However, its "flattish" outlook for Q4 and reiteration of its long-term 6%-8% revenue growth outlook sent shares lower. He sees the pullback as presenting a buying opportunity, as he views the outlook as conservative, particularly for FY20, Marchetti said. He expects additional market share gains amid customer spending increases in support of 400G/800G adoption and preparation for 5G deployments and reiterated a Buy rating with a $54 price target on Ciena shares.