Share of Zscaler (ZS) - Get Report rose by as much as 3% on Tuesday after Berenberg upgraded the cloud security company's stock to buy from hold.

Berenberg analyst Joshua Tilton is expecting "continued sustained growth" after attending the company's user conference, according to Bloomberg.

"Zscaler has superior technology relative to legacy competition," the analyst said, adding that he had "never met a group of customers as positive about a product as these were about Zscaler's."

Zscaler shares were trading at $51.98 before setting back to around $50.52. The stock has risen more than 20% over the past year, but is trading more than 40% below its record of $89.54 reached in July.

The shares tanked in September after the company reported disappointing guidance for the full year.

Berenberg has "increased confidence in the sustainability of the multiple" following the drop.