Why am I not able to place market orders for some index and all stock option contracts at Zerodha?
A market order is an instruction to buy the specified quantity of a scrip irrespective of the price it is available at. In the case of illiquid contracts, the bid/ask price could be at a price far from the last traded price or theoretical price of the contracts.
We have had customers placing market orders without checking bids/asks on such contracts and losing money due to trade execution at arbitrary prices. Market orders are hence blocked for illiquid index options and all stock options.
You will be able to place market orders for Nifty and Bank Nifty options only for the current and near weekly/monthly expiries where liquidity is usually adequate. Market orders are blocked for:
- All weekly expiries other than the current and next week
- All monthly expiries other than the current and next month
- Deep ITM contracts (which are more than 5% in the money)
Market order AMOs are blocked for all monthly index options. However, you can place limit orders for any of these contracts at or greater than the best bid/ask price to instantly execute your trade like a market order.