Are the real-time quotes accurate?

The bid/ask is accurate and very close to the NBBO, but the last price may not match other data sources because the trade might have occurred on another exchange. Volume is also not accurate in terms of an absolute value because the data does not include all exchanges, but we have found that the percentage above and below normal is fairly accurate and that is why we graph volume in those terms. For our purposes, the data source works well. Before placing a trade, we urge you to check the prices and charts with your online broker when placing trades.