Is it possible that Bid/Ask can cross between BSE and NSE?
ie
eg
BID in NSE is > ASK in BSE?
In that case someone can easily buy in BSE and SELL in NSE at profit?
Want to know if such a thing happens so that I think of making an algo in this?
If not then why it doesnt happen. Are exchanges doing something to prevent it?
Hi Saurabh,
If you are referring to an arbitrage trade across exchanges, it is possible. You can buy in NSE and sell in BSE if you encounter a profitable trade. But this is possible only when you hold the shares in your Demat account.
Also, you cannot switch between exchanges when you are trading Intraday. If you buy a position in, let’s say, NSE, you have to square off the position in NSE only; doing otherwise will create two different intraday positions.
More about this is explained on our support portal, I have attached the links below for your reference:
Hi @kulsum_khan , thanks for the response. This makes it clear that intraday one cannot buy and sell on different exchanges.
Any idea if this is zerodha only restriction or it is mandated from exchanges?
Also first part of my question. Do prices cross between exchanges?
Hi Saurabh,
Due to interoperability concerns and since it creates two different intraday positions it is not advisable by Zerodha to trade intraday across exchanges.
Yes, prices cross between exchanges depending on various factors like trading volume, liquidity etc across exchanges.
Hope this helps 
Thanks @kulsum_khan . So does that mean interoperability is still not implemented? Is this not operational from SEBI side or delay at Zerodha side?
As mentioned in the attached article above, Zerodha is operationalizing interoperability in a phased manner.
But this article says it is going to be implemented around July 15 2019 for cash.
So it is still not done.
I am just asking
It will soon be implemented fully
Before instant unpledge or after ? 