If a buy order matches with multiple sell orders say 50 orders in one go, then when will the ticker top buy / top sell / market price will change? a) After buy order matches with first sell order? or b) After buy order matches with all sell orders? or c) For every order match?
Assuming you're asking about the "last" market price, it will change on the first full lot (100 shares or more) transaction at the price.
After checking multiple exchanges, I found that if a order matches with multiple order in one go then only after last transaction ticker prices get changes.