Personal Finance. Usually, the investment banks want to lock up all insider sales for at least 90 days after the IPO to give the fledgling stock a good period of time to find a natural equilibrium between buyers and sellers. Yeah, all of that was pretty funny today. Everyone involved in the IPO — company management, auditors, accountants, the underwriting banks, and lawyers from all sides — attends this meeting. Depending on demand and how deal is structured, etc, price range may change. Investment banks serve a number of purposes in the financial and investment world, including underwriting of new stock issues, handling mergers and acquisitions , and acting as a financial advisor.