Why does the Bars endpoint return a “0” value for a given period?

Bars are determined by last sale eligible transactions within a given period during regular market hours. Last sale eligible rules are not applied during pre-market nor post-market. During regular market hour, if there are no last sale eligible transactions within the period it will result in returning a value of “0” for open, high, low, and close. It is possible for volume to be the only value returned as volume considers all trades for a given period. If all values are “0”, there will be no Bar returned. Client can choose to not show the bars with ‘’0’’ value for open, high, low and close on the UI.