I was wondering. I know that BATS is the third largest market center for stocks. If I use a service like freestockcharts.com, which uses the BATS exchange for its data, will there be any difference with a real streaming service that gets its quotes from all of the ECNS? If there is a difference, then by how much?
Are the securities you are looking at using BATS as their primary listed exchange? If yes, then there will not be a tremendous difference (except in depth of book and size, but not price), if no, then there will be a significant difference in terms of price, size and depth of book.
Here is what I am trying to do. Sometimes I am not at my home computer or using my home network which I am confident is secure. However, sometimes I am out at different places with my laptop using an unsecure wifi network or at a computer that is not my laptop. I don't want to login into my brokerage account to get charts and quotes on unsecured networks/computers. So there is a service called www.freestockcharts.com where I can see the market and get quotes/charts, but it uses the BATS exchange. I honestly don't know which stocks primarily trade on the BATS. Lets say some of the more popular stocks like Apple and Google. Would those have much of a difference then a real ecn?
It depends on what you are after. If you are manual trading and you don't care about a few pennies then the prices will be as good as any other service. If you care about pennies, the exact spread and depth of book then you probably want a real data feed. If you are trading market orders via a retail broker then none of it matters anyway. Why are there differences - because you will normally see a securities primary listed exchange have the best price and volume. Securities often trade on other exchanges - but the other exchanges are not always on the NBBO. To me, pennies are a big deal, to others maybe not so much.