Market-on-Close Order
A Market-on-Close (MOC) order is an order to buy or sell a security at the best available price at market close. In India, closing prices are determined through a closing auction mechanism, and MOC-equivalent orders participate in this process.
What Is a Market-on-Close Order?
An MOC order executes at the day’s closing price, not during regular trading hours. It ensures participation in the closing auction at the final price of the day.
This is the opposite of a Market-on-Open (MOO) order. MOC orders are useful when the closing price specifically matters for strategy or benchmark purposes.
India’s Closing Price Mechanism
Indian exchanges (NSE and BSE) calculate the official closing price as the volume-weighted average price (VWAP) of all trades in the last 30 minutes of trading (3:00 PM to 3:30 PM). This is different from just the last traded price.
From 3:40 PM to 4:00 PM, NSE conducts a closing market session where participants can trade at the official VWAP closing price. This session functions like an MOC order mechanism.
Why Use MOC Orders?
– Mutual fund managers need to value portfolio holdings at the official closing price; MOC orders allow execution at that exact benchmark price
– Index rebalancing often uses closing prices to add/remove constituents
– Institutional investors executing against benchmark closing prices
– Portfolio managers ensuring their transaction price matches their cost of holding (NAV calculation)
Practical Example
A large equity mutual fund receives Rs 100 crore in redemptions at the end of the day. To exit positions at the official closing price (which determines today’s NAV), the fund manager places sell orders in the closing session (3:40-4:00 PM on NSE). Trades execute at the official VWAP close price, ensuring fairness to all redeeming investors.
Key Takeaways
– MOC orders execute at the closing price; designed for execution at the official day-end price
– India’s official closing price is the VWAP of the last 30 minutes of trading (3:00-3:30 PM)
– NSE’s closing market session (3:40-4:00 PM) allows trading at the official close price
– Used by fund managers for accurate NAV-linked execution and index-rebalancing purposes
– MOC orders reduce tracking error for benchmark-sensitive institutional portfolios
