Market orders aren't allowed on Trade-to-Trade (T2T) or Debt category instruments — the exchange only permits Limit orders on these, so you always need to specify a price rather than trade at whatever price is available.
Why does the exchange restrict market orders here?
A market order executes at the best available price on the order book, whatever that turns out to be. T2T stocks (the BE series) and Debt category instruments (bonds, NCDs) typically trade in low volumes with wide bid-ask spreads. Letting a market order execute at "whatever price is available" on such a thin order book can fill you far from the last traded price. Requiring a Limit order means you always know and control the price before it executes.
What should I do instead?
Place a Limit order with the price you're willing to transact at. If you want the order to fill quickly, set the limit price close to the current market price — but you decide it, rather than the exchange filling you at an unpredictable price.
Things to keep in mind
- This restriction applies to the Market order type only — you can still place Limit orders on T2T and Debt instruments.
- T2T stocks also don't support Intraday orders, since the exchange requires compulsory delivery on them — see Why can't I place an Intraday order on some stocks?.