It is because some people are getting into the IPO as bulk and selling on the listing price to make spot gain or loss. When they are playing in bulk their net spot gain will be higher. They also tend to sell if some IPOs open lower as they would be nervous price will fall even further. These group of people are playing in volumes and mostly into majority of IPOs. so, they dont care loss or profit of inidvidual IPO as long as their net sum is in profit. Plus if they will make some loss they will deduct that in tax.
