Union Pacific rises after Susquehanna upgrades to 'positive'

Shares of railroad operator Union Pacific UNP.N rise 1.2% to $228.60 in premarket trade after Susquehanna upgrades stock rating to "positive" from "neutral"

"We view UNP's share price underperformance as an opportunity vs. a better-than-feared volume backdrop for rails" - brokerage

Says UNP's volumes remain healthy and its network is fluid

Also trims rating on peer CSX CSX.O to "neutral" from "positive"; shares marginally down premarket

As of last close, S&P 500 Rail Transportation sub-index .SPLRCRAIL up 1.56% YTD