Market Status Change, MC message is received when the exchange changes its trading state. E.g. the change from ‘Pre-open’ to ‘Open’ or from ‘Pre-close’ to ‘Close’ will generate a MC message.

Stock Open Price / Close Price message is received just before the market opens or after the market closes.

Index Information message is received every time the following scenario happens:
a) When a trade has occurred for a particular stock in the regular market
b) When a new order for a particular stock changed the current best market
c) When a non regular trade occurred for a particular stock in a market or with a non-standard settlement cycle like delayed delivery for a particular stock
d) When an equity summary report is sent from the exchange for a particular stock when moving into pre open
e) When moving towards the closed state
However, depending on the exchange, you may receive at most ten (10) such messages which correspond to the exchange’s indices.

Stock Information message is received every time the following scenario happens:
a) When a trade has occurred for a particular stock in the regular market
b) When a new order for a particular stock changed the current best market
c) When a non regular trade occurred for a particular stock in a market or with a non-standard settlement cycle like delayed delivery for a particular stock
d) When an equity summary report is sent from the exchange for a particular stock when moving into pre open
e) When moving towards the closed state

Market by Price message is received when an activity affects the top 5 price levels on the market.

Market by Order message is received when an activity affects the top 10 orders on the market.

Stock Summary, SS message is received just after the market closes. In addition, you will receive these messages every time you will reconnect to us. Furthermore, you will receive summary message for each stock listed. In case of lost connection, SS messages are sent to clients as well for receiving the latest market activity.

Index Summary, IS message is received just after the market closes. In addition, you will receive these messages every time you will reconnect to us. You will receive IS message for each index listed. In case of lost connection, IS messages are sent to clients as well for receiving the latest market activity.

Stock Quote, SQ message is received every time an “ask” or a “bid” activity happens. Depending on the exchange, SQ might be received when the scenarios enumerated in both SI and II happen.

Heart Beat, HB message is received every minute as long as you are connected to us. Thus, you will still receive HB messages even when the market is closed. In the raw feeds scenario, clients are disconnected if XData is disconnected from the exchanges (e.g. after market hours). But in the unified feeds scenario, clients remain connected to XData 24x7. We will send Heart Beat in this case.