By analysing those orders, the market maker can get a sense of how much demand there is to buy a particular stock versus how much is available to sell.
Their goal in doing this is to try and figure out what the optimal price is that will allow for the maximum volume of buying and selling in the stock when it begins trading.
So market makers never actually sell a new share at market open, they wait to see what the demand is and then set the price?
Seems like a pretty strange process. If you’re a buyer it’s in your interest for all buyers to hold off as long as possible to ensure the price does not get raised.
If you’re a seller, you could potentially do something like put in loads of buy orders knowing that the orders will not be executed right away but you could push the price up at no extra cost to yourself.