Let's say I'm looking at a minute stock chart during a trading day. Will E-Trade and TD-Ameritrade for example, show a different price on the minute by minute chart? (or 5-minute chart, etc.)
A one minute chart is a effectively a derivative of price because the provider is collating 60 seconds of data and creating a data point. It's very reasonable to expect that one platform may do this faster than another. It's also possible that other technology issues can add a tiny delay to the process (server speed, clock issues, starting/ending point of the minute, etc.).
One would expect that the current trade price/volume info for two platforms should be identical but I can attest to the fact that it's not. Occasionally, I have seen one of my brokers lag another by a second or two. And if I'm seeing it on the few stocks that I'm intently watching at a given moment, it must be happening an awful lot since there are many, many thousands of stocks trading.
Will E-Trade and TD-Ameritrade for example, show a different price on the minute by minute chart?
It is possible they show different charts, but this is not the same question as
Is a stock's price different across trading platforms?
because a different price may simply be an issue i.e. of time being off on a server. There is a lot of technology that can go wrong.
Price between platforms that follow the same rule SHOULD be identical, but it may differ base on technological issues between platforms (i.e. a data feed is out because a router failed, i.e.).