Were you stunned with Paytm's inventory market debut? India's largest IPO until date closed 27% beneath the difficulty worth on itemizing day. It impacted sentiment in all the inventory market.Paytm's flop present shouldn't come as a shock to you as this isn't the primary time a high-profile IPO has eroded buyers' wealth on itemizing day. There have been a number of such IPOs prior to now.Let's check out the mega IPOs with the worst debut day efficiency. We have thought of IPOs with challenge dimension of greater than Rs 1,000 crore.#1 One 97 Communications (-27.2%)Shareholders of One 97 Communications, the operator of main digital funds platform Paytm, had been caught in a whole bear lure on itemizing day. Shares of Paytm began their journey with a 27.2% fall over its IPO worth final week on Thursday. Shares hit the decrease circuit at round 3:00 pm, and buying and selling within the inventory was halted.This selloff worn out round Rs 40,000 crore of investor wealth on the primary day. Interestingly, that is greater than all the market cap of firms like TVS Motors, Tata Communication, MRF, and Oberoi Realty.That's not all.Paytm shares are once more caught up within the selloff as we speak. They are down over 12%.Due to this large selloff, the markets regulator is now planning to query the funding banks that dealt with Paytm's IPO. The regulator will search their views on why the inventory tanked on the itemizing day.It additionally plans to look at if any feedback made by the corporate officers or the bankers might have misled buyers.The weak itemizing was on the playing cards as market specialists had been already cautious on Paytm's excessive valuation, muted investor response, and loss-making enterprise. But such a giant fall was sudden.But regardless of the dip, the corporate clocked a valuation of over Rs 1 lakh crore.#2 Coffee Day Enterprises (-17.6%)Shares of Coffee Day Enterprises closed down practically 18% at Rs 270, towards its challenge worth of Rs 328 on debut. Coffee Day Enterprises, which runs Cafe Coffee Day (CCD) retailers, had raised Rs 1,150 crore via its IPO. The challenge was subscribed 1.64 occasions at a worth band of Rs 316-328 per share.In March 2015, the agency had mobilised Rs 100 crore in a pre-IPO funding from Nandan Nilekani and Rare Enterprises (promoted by Rakesh Jhunjhunwala), amongst others.At a press convention forward of its IPO, V G Siddhartha was requested why its provide worth was decrease than a personal placement just some months earlier. He replied that he needed to go away some cash on the desk for retail and institutional buyers.In 2020, buying and selling in Coffee Day shares was suspended for not complying with itemizing norms pertaining to submission of quarterly monetary outcomes. Shares resumed to commerce this 12 months 26 April onwards.Since itemizing, shares of the corporate have been on a downtrend and have hardly traded many occasions above its challenge worth.