with us stock markets set to open in two hours prometheus biosciences inc rxdx was up 695 in premarket trading and roivant sciences ltd roiv was up 125 algonquin power  utilities corp aqn mt bank corp mtb and horizon therapeutics plc hznp were all posting gains of at least 3 in early trading check point software technologies ltd chkp and teradyne inc ter had posted declines falling 40 and 34 respectively