Whenever a tech company IPOs and the stock trades up on the first day, all of the pundits rush to exclaim the company was mispriced and the bankers took money away from the company!
In reality, there is a very thin amount of stockholders that can and want to sell on the first day of trading so when demand > supply - the price goes up accordingly. There are also strong incentives to want to create a happy base of strong shareholders & liquidity providers - all of which favor this continued dynamic of increasing prices on the first day of trading.