From the conversation
“CAS is a very good thing for our markets. The actual impact has been on the derivatives side.”
On ten days of evidence
CAS went live on 3 August. By 14 August the desk had ten sessions of data — enough to describe the change, not enough to treat it as settled. The cash close itself is not the dispute. The question is what a 15-minute auction does to a derivatives market that used to decide into 3:30.
On the 3:15 decision
The practical boundary for a derivatives trader moved earlier. The session still prints into 3:30, but the decision that used to sit at the cash close now has to be taken around 3:15. That is not a small clock change. It compresses the last useful window of the Indian trading day, especially on expiry.
On a small book pricing a large one
CAS turnover in the first stretch was roughly ₹1,200–1,400 crore a day — about 1% of the cash book that trades from 9:15 to 3:15. That 15-minute print now sits over a much larger derivatives book. The close can be demand and supply. It can also be a thin window asked to settle a far larger market.
On active traders made passive
Shai used a cricket-ground picture: players who were on the pitch have been asked to sit in the stands. Derivatives traders can watch the CAS close. They cannot participate in it. For a market whose daily premium turnover is not a small book, that is the structural point — not a prediction about where the next expiry lands.
The excerpts above are from Shai Coelho's remarks on a CNBC-Awaaz panel. The full discussion, as broadcast, is available on YouTube. Market commentary is educational and observational; it is not investment advice or a trading recommendation.