Technically the structure is still bullish and Nifty stands at the strong polarity support, failing to hold which the index is likely to see a further correction towards 17,650 – 17,500 zones. Only a sustained close above the 18,200- 18,250 zone is likely to trigger bullish momentum toward 18,450 – 18,500 levels,” Rohan Patil, Technical Analyst, SAMCO Securities, said