Comparing listing gains across many IPOs in the same period gives a sense of overall market appetite rather than individual company quality.
Quarterly results published after listing are the first independent check on whether the company is performing as described in the prospectus.
An easy example
A share issued at Rs 645 listed at Rs 596 and later traded at Rs 628. It is still below the issue price despite recovering from listing day.
Important note
Short-term movement after listing is influenced by demand and market conditions, not only by the company's performance.
Common mistake
Judging a company on its first week of trading alone.