NEW DELHI: Erasing the gains of over 1,000 points, equity barometer Sensex slipped into the red in afternoon trade on Thursday on poor show of select heavyweights, including HDFC Bank, ITC and TCS.Headline indices Sensex and Nifty made their fresh record highs at 40,124.96 and 12,041.15 in the first half of trade, buoyed by the early vote count leads that showed Narendra Modi-led NDA getting a decisive majority.However, the market failed to hold the altitude and witnessed bouts of volatility.After surging over 1,000 points to hit new high of 40,124, BSE Sensex not only gave up all the gains but also slipped 299 points, or 0.76 per cent, into the negative territory to end at 38,811. Its NSE counterpart Nifty, suffered a similar fate to end at 11,657, down 80.85 points or 0.69 per cent. The 50-pack had hit a high of 12,041 in the first half of the day. This was the biggest intraday drop for the market in 11 years."Indian equity market as expected touched the historical figure of 12041 and made a new all-time high. Markets seem to have discounted the magical and mandate that is going with the BJP. At the same time, we see there is some profit booking that is coming in at higher levels. The derivatives data that was pointing the range to be 12100 - 11500 stands firm at this point of time," said Mustafa Nadeem, CEO, Epic Research.In the Sensex index, 19 stocks were trading with gains and 12 were incurring losses.IndusInd Bank, YES Bank, ICICI Bank , Hero MotoCorp and State Bank of India were among the top gainers in the 30-pack index.On the other hand, Vedanta, ITC, HDFC Bank, TCS and Bajaj Finance were among the top losers.FMCG, IT, consumer durables and metal were among BSE sectors that were trading in the red.BSE FMCG was the top loser among the sectoral indices, falling over 1 per cent, due to losses in shares of ITC, HUL, United Breweries, Tata Global Beverages and Marico.In the IT pack, TCS, Infosys and Tech Mahindra declined amid rupee's rise against the US dollar.