Shares of open-source software maker Hortonworks Inc. are up 2.7% in premarket trading Monday after Monness, Crespi, Hardt & Co. analyst Brian White upgraded the stock to buy from neutral. "Despite delivering a couple of solid quarters this year, Hortonworks' stock is actually down in 2018 and the second-worst performer in our coverage universe," White wrote. He said that the stock's performance could be reflective of a weak outlook from peer Cloudera and a strong 2017, rather than the company's own trends this year. White also said that the stock is trading at a discount to peers on the basis of enterprise value to revenue. "We believe this valuation gap can narrow as the year progresses and thus we believe Hortonworks represents an attractive value at current levels," he wrote. Shares are down 15% this year, while the S&P 500 has gained 14%.