Bid / Ask field contains NULL values. Why?

[Shah Yahya]

Hello gents,

I have a few questions about the ticks history in the symbols (MT5)

1. It seems that there are empty (null) value in the bid & ask fields. Why does it happen? Does it even happen to all brokerage or it depends on each brokers settings?
2. In this MT5 documentation, there's a few flag declaration (i.e. each number of flag represent changes in bid/ask) but there are no full list. Where can i find those details?

p/s : last and volume is empty (I assuming spot market doesn't have that information?)

Thanks so much for any explanation!

[Soewono Effendi]

It is safe to assume there were no price changes when field is null.