The investment bank sells a lot of shares to its own preferred clients. If the price then drops (because the initial offering price was too high) those preferred clients lose money.

So the bank has every incentive to price it low, and usually does. So when the market goes even lower, we know that the IPO was done out of desperation and that early investors who had influence over the IPO price were eager to dump some or all of their positions.

One day is too soon to know for certain that this happened. But if the price is still down a week or two later then it probably did.