Once listed an IPO is just a regular stock, that any investor/trader may buy at its market price. Unlike an IPO there is no minimum/maximum lot
size specified for listed stocks, however the price it which the stock lists on the markets may be higher or lower than the IPO price.
Listing gains refer to the appreciation in a stock’s listing price, vis-à-vis its IPO price. I.e. in case a stock for whom the IPO price was ₹100 lists at ₹110 at the stock exchange(s). It is said to have listed at 10% gain.
Listing loss refer to the decline in a stock’s listing price, vis-à-vis its IPO price. I.e. in case a stock for whom the IPO price was ₹100 lists at ₹90 at the stock exchange(s). It is said to have listed at 10% loss.