What happened Shares of Ciena (NYSE: CIEN) plunged by 30% last month, according to data provided by S&P Global Market Intelligence. Most of that decline occurred when Ciena reported fiscal third-quarter results in early September. So what Revenue in the fiscal third quarter crawled up 2% to $976.7 million, which resulted in adjusted earnings per share of $1.06. While those results topped consensus estimates, investors were disappointed by the optical networking tech company's guidance. Image source: Getty Images. The coronavirus pandemic has significantly impacted Ciena's core business, which resulted in a lackluster outlook for the fiscal fourth quarter. Ciena expects revenue in the quarter to be in the range of $800 million to $840 million, which is well below the $994.4 million in sales that analysts were modeling for. Now what Ciena warned that the coronavirus outbreak had made operating conditions "complicated" and it now takes more time to deploy and activate new equipment. The company is also struggling to ramp up international deals due to the pandemic, while visibility is suffering from deteriorating market conditions. "As I alluded to in my opening remarks, late in the fiscal third quarter, we began to see some of the effects of COVID-19 manifest in our business to a greater degree than anticipated, as well as increased economic uncertainty," CEO Gary Smith said on the conference call with analysts. "Specifically, we began to experience a meaningful slowdown in orders and a softening of our outlook." 10 stocks we like better than CienaWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Ciena wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of September 24, 2020 Evan Niu, CFA has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.Source