We only display "free real-time" data for 20 minutes on our charts,  After that, we replace the "free real-time" bar(s) with delayed "official" bars from the major exchanges.  For 1-minute and 5-minute charts, we place a vertical, dashed yellow line on the chart to show where the free real-time bars end and the official bars begin.

To learn more about "free real time" please refer to this blog article.