Nifty trades below 8,300; Tech Mahindra slips 13%, Tata Motors down 5%: The markets have opened on a negative note, tracking weak cues from the global front. At 9.35 am, the Sensex was at 27,414, lower by 117 points or 0.4% and the Nifty was at 8,293, down 47 points. The broader markets are also witnessing selling pressure, with the mid-cap and small-cap indices shedding about 0.5% each at 10,577 and 11,108 respectively. The impending derivative expiry on Thursday is likely to add volatility to the market proceedings, given the rollovers from the ongoing May F&O series to the June series. The rupee has breached the 64 level in opening trades, down 7 paise to 64.05 a dollar from 63.98% in the previous session.