Can anyone explain this BO failure?

I placed BO for 50 shares to be bought at 527 of CAPF sharp at 9:15:01

My order got executed at 517.45.

Did I made some error or it is system error?


Well you are willing to buy a share at Rs.527 while the current market price of the share is 517.45 at that moment. So basically you are bullish on the stock expecting the share price to go up.
As the price was below your expected buy price the system excauted the trade.