First, many instruments do not trade 7/24. Thus if you are showing a chart that covers beyond the time that these symbols are trading, you expect gaps in the chart.

Second, you may not have the complete historical data on hand and that your data vendor for some reason did not deliver the data to NeoTicker on the first request. If that is the case, select the chart, then point your cursor at the blank area and press the key F11. NeoTicker will try to obtain the data again from your data service for the missing data automatically.