In stocks market, how can I Exploit the bid ask spread ? Basically what kind of information these 2 give you?

Question

and how they effect the price ? Is that true that for a market order, the price you pay is greater than the ask price you see now ? By the way how fast are those data updated on yahoo finance ?
As you see this question is mixed of several questions; you are welcome to answer a part or the entire thing. And thanks for taking time in advance.

Answer 1

I don't see how you can exploit bid/ask spread.
only the sell price matters and there is no way of telling what that is until it happens. also bid/ask is usually close together, and you pay a commission on buying and on selling, so there is no room for profit here

I would think yahoo data is delayed, you have to subscribe to pay services to get real time info,
Without real time info, and day trading is doomed to fail

Market order, you pay whatever price is asked for when the order is executed...you don't control your cost by naming a price

Answer 2

Well, it used to be done successfully with limit orders in the past (by those who knew what they were doing). But from what I understand, things have changed since then and it's now extremely difficult if not impossible to exploit the bid/ask spread. I wouldn't even waste my time giving it another thought, if I were you.

Answer 3

as far as I know you can not. The bid is what someone is willing to buy for. The ask is what someone is willing to sell for. It is sort of like selling wholesale and buying retail. The best way to exploit it is to not buy stocks with a large spread. Therefore, when you go to sell, you will not face a very large discount.

Answer 4

If you see to large an bid-ask spread, almost always you are in a highly iliquid stock, which you may have trouble selling later. Beware of low volumes.