As BSE has 4 one week expiry in a month, want to know that on BSE website, it is written that there are two weeks expiry also, can someone explain then total how many expirys are there on BSE?

General
2

Nishant,

Like Nifty futures has present, near and far contracts. They are also called 1st month, 2nd month, and 3rd month contracts.

Similarly BSE has W1, W2, W3, W4 for Dec. So if you trade on W2, that means you are trading on Dec two weeks expiry.

3

I am not sure about BSE, But in NSE monthly expiries open 3 months before, So If you buy an expiry which is little less than 3 months from now, then you call it as that you have bought a 3 month expiry. If the same thing you thought this is not the right time and wait for another 2 months and buy then, then you could call it a 1 month expiry since only little less than 1 month is left out.
But that particular expiry contract will have history of total 3 months after which it will cease to exist.

So what I am trying to tell is whether it is a 2 week expiry or 1 week expiry is based on how many days left out for expiry.
Again someone correct me if I am wrong!