Indian stock markets opened on a marginally positive note in early trade, with Sensex rising 27 points to 77,331.21 and Nifty 50 gaining over 37 points to 24,131.44. However, the rupee weakened to 94.04 against the US dollar, signaling currency pressure. In global commodities, Brent crude oil futures traded at 109.50 per barrel, indicating mixed market cues.