As the counting of votes began on Thursday morning, the stock market witnessed gap-up opening in the pre-market session with the NSE Nifty 50 index surging as much as 159 points to record high of 11,897.

On the other hand, the S&P BSE Sensex surged nearly 500 points to record high of 39,606 as early trends showed NDA advancing on over 200 parliamentary seats.

The latest trends show NDA notching over 300 out of 542 seats which means the Sensex could even breach the 40,000-mark in a scenario where BJP emerges as the single largest party. Nifty, too, is expected to hit record highs and cross the 12,000-mark.

As per reports, one share in the Nifty 50 basket was trading higher led by the IndusInd Bank's 6.2 per cent gain. Indiabulls Housing Finance, State Bank of India, Zee Entertainment, Power Grid, Adani Ports, Yes Bank, HDFC, ICICI Bank and Larsen & Toubro were also up between 2.5 and 5.2 per cent each.

Mid- and small-cap shares were also witnessing buying interest as the S&P BSE MidCap and S&P BSE SmallCap Index advanced over 1.5 per cent each.

According to traders, investor sentiment was boosted by initial trends that suggested a win for the ruling NDA. Amid market euphoria, the rupee also appreciated 26 paise to 69.40 against the US dollar in opening trade.

The 30-share index zoomed over 2 per cent to hit an intra-day high of 39,901.59. Similarly, the broader NSE Nifty too spurted more than 2 per cent to touch a record of 11,968.95.

Earlier on Wednesday, after swinging over 300 points during the day, the 30-share index ended 140.41 points or 0.36 per cent, higher at 39,110.21. The gauge hit an intra-day high of 39,249.08 and a low of 38,903.87.

In similar movement, the broader NSE Nifty rose 28.80 points, or 0.25 per cent, to 11,737.90.

While, on Monday, the Sensex registered its biggest single-day gain since September 2013 after exit polls showed the National Democratic Alliance (NDA) party led by Prime Minister Narendra Modi will retain power for a second consecutive term.

(With Inputs From PTI)