When you trade stock online you will have access to an execution only platform that you login to. From here you can deal according to how your account is set up. Usually these brokerage companies will require you to deposit a cash amount prior to doing any online stock trading. Once you have available funds you can usually execute trades in real-time providing it is below normal market size.

If you want to do trading with very large sums of capital or trade illiquid stocks, you may need to deal with your broker over the telephone as they often cap online trades according to NMS ( normal market size ). When you call your broker they will then deal directly with the market maker to confirm the trade or override it manually. Often when you trade in blocks over the normal market size you will end up paying slightly more on the offer or slightly less on the bid.

If the stock is relatively liquid you can often get improvements on the yellow strip ( touch price ) price when online stock trading. Once the transaction has gone through as a buy or a sell trade, your account is usually updated at the same time to reflect these changes from a monetary point of view. It often does not cost very much to set up an online trading account as there is no risk to the brokerage company if you have cash on deposit before you execute any trades.