The price on charts and depth of market, never hit the price at which I placed my order, but my order got executed, why is this?
On any given day on the exchange, there are millions of transactions. Each of these transactions is represented by a tick. It is technically impossible for any trading platform to show all the ticks, especially live that too on a normal broadband connection.
So all trading & charting platforms will display 1 tick (buy/sell transaction on the exchange) per second on the chart, whereas in that second there would’ve been hundreds of ticks/transactions. This is why it is quite possible one will not see the Stop Loss or Limit price that got executed on the chart.
If you really want to see all the ticks, NSE does have Tick by Tick data feed which is a lot more expensive than the normal data feed and will have to be subscribed to through any of the authorized NSE data vendors (Not all of them give you tick by tick data). Also to be able to make the best use of this tick by tick data, you should ideally be on the NSE co-location which would mean that your systems are inside NSE itself so that accepting all the millions of ticks will be quite efficient.
Tick by Tick data is usually what professional High Frequency and Arbitrage trading firms use, don't think there is anything much a normal retail trader can do with it.
Also, if a trade is executed you can be rest assured that the scrip was traded at that price and it can be reconfirmed on the NSE Trade verification module within 5 days from when it was executed and you could also see the day's range on the daily Bhavcopy and you will see your SL/Limit price within this range. The links to BSE & MCX trade verification are given here.
To learn more refer these post on tradingqna -