Question about opening a brokerage account?

I sold an investment house and received the closing check from the real estate lawyers. I want to open a brokerage account, most likely with Merril Lynch or Schwab. How long do they hold the check when it is first deposited with them? Normal banks hold them for like 5 business days. Do these brokerage houses do it quicker? Would I be able to use the money in a day or two?