Domestic stock markets opened slightly lower today amid investor caution over rising US-Iran tensions. The Sensex dipped 225.65 points to 82,272.49, while the Nifty-50 declined 47.80 points to 25,406.55. Bank Nifty also slipped 111.70 points to 60,627.85. The Indian rupee was trading at 90.95 against the dollar, reflecting the global uncertainty.