After-Market Orders (AMO) & Order Execution

An After-Market Order (AMO) lets you place a buy or sell order outside live market hours. The order is held by ATS and released to the exchange when the market (or the relevant pre-open session) opens on the next trading day. It is built for clients who cannot watch the screen between 9:15 AM and 3:30 PM and want to plan trades the evening before.

It does not execute the moment it is placed. It is queued and released at market open, after which it competes for a fill exactly like any other order — subject to price, time priority and available liquidity. Placing an AMO is not a guarantee of execution.

Typically one day. If it is not filled on the next session’s open or through the day, it is auto-cancelled at end of day. A plain AMO is a single-day instruction; confirm whether any GTT/GTC-style persistence is enabled in your ATS account.

A pre-open order is placed by the client during the 9:00–9:15 AM call-auction window. An AMO is placed outside hours and is routed into the opening process automatically. For equity (and now current-month futures), an AMO effectively becomes a participant in the pre-open auction. For instruments with no pre-open (e.g. options), the AMO simply enters the normal session at 9:15 AM.

Both are generally allowed. A market AMO has price protection applied (capped relative to the previous close) so it cannot fire at a runaway price. A limit AMO only fills at your price or better. Special order types — stop-loss (SL/SL-M), IOC and cover/bracket orders — are generally not permitted as AMOs.

Because NSE and BSE introduced a pre-open session for equity derivatives from 8 December 2025. AMO collection for contracts that participate in the pre-open (current-month index and stock futures) now stops around 8:57 AM, since those orders must be inside the auction before it begins. Options and far-month futures (outside the last five days before expiry) still accept AMOs later.

It is rejected. The AMO route is closed from 9:15 AM to about 3:45 PM, and also during the 9:00–9:15 AM pre-open window itself. There may also be an overnight maintenance gap during which AMOs cannot be placed — exact windows are configurable in ATS, so confirm the current values.

Through a call-auction in the pre-open window (9:00–9:15 AM for equity; the same window for participating F&O futures since Dec 2025). Order entry runs 9:00–~9:08 AM (place/modify/cancel), closing at a random moment between the 7th and 8th minute to prevent last-second manipulation. Order matching (~9:08–9:12 AM) computes the single equilibrium price — the price at which the maximum quantity can be matched — with no modification allowed. A buffer (~9:12–9:15 AM) transitions into the continuous session at 9:15 AM.

At the equilibrium price the engine matches in this order: eligible limit orders against limit orders first, then residual limit orders against market orders, then market against market. Within each level, price–time priority applies.

Unmatched limit orders carry over into the normal session at their limit price, keeping their original timestamp (price-time priority preserved). Unmatched market orders are converted to limit orders at the discovered equilibrium (open) price and moved to the normal session. If no equilibrium price is discovered, market orders are carried over at the previous close as the reference.

Options, spread/combination orders, and contracts on an ex-date for certain corporate actions are excluded from the F&O pre-open. Options begin trading directly in the continuous session at 9:15 AM, so their “open” is the first traded print, not an auction equilibrium price.

Take the common example: an AMO sell on NIFTY 23100 PE, quantity 65, limit 49.00, placed at 09:08:22, status Open (0/65); after open the contract showed Open 50.00, High 50.00, Low 31.55, LTP ~39. The decisive fact is that this is an option, and options have no pre-open auction. So “Open = 50” is not an auction equilibrium price — it is simply the first traded print in the continuous session at/after 9:15 AM. There was no auction in which a 49 sell could claim the 50 open.

No. A limit sell at 49 means “sell at 49 or higher”, and for it to fill it needs a resting buy order at 49 or above, with your order at the front of price–time priority for that level. Open = High = 50 tells you 50 was the highest price traded all day, and only a limited quantity changed hands there. If the bids at 49–50 were thin and were consumed by orders ahead in time priority, the 65 lots never met a counterparty.

Yes. An AMO is released to the exchange at open. Orders already resting in the live book — and orders placed natively at 9:15:00 — can sit ahead of a released AMO in time priority at the same price. So even a “marketable-looking” limit can miss the first few prints at the top of the range.

High 50, Low 31.55, LTP ~39 means that after the opening prints the bid dropped well below 49 and never recovered to 49 or above. So after the first instant, a 49 sell was no longer marketable — there were no buyers at 49+ for the rest of the move. The result, 0/65 filled, is correct, expected behaviour, not necessarily a system fault.

For a thinly-traded option with Open = High, no — it is normal. The open print can be a tiny quantity and the very next ticks can be below your limit. The order behaved correctly by not filling below its limit.

Investigate if the exchange order log shows the order was accepted and live before the first trades at your limit, there was clear traded volume at your limit or better after the order was live, and there was still zero fill. That points to a routing/RMS/OMS delay rather than market mechanics. Until the exchange trail confirms that, treat it as a genuine non-execution.

Pull the NSE order/trade log for the contract and compare timestamps: (a) the exchange acceptance time of your order versus (b) the timestamps and prices of every trade printed at your limit. If no trade at your limit printed after the order was live, the non-execution is genuine and the order behaved correctly.

Insufficient funds/margin (buy) or insufficient holdings (sell) at the moment of release; a limit price outside the permitted band (a percentage of reference price or the day’s circuit); a disallowed order type for pre-open (IOC, disclosed-quantity, certain ETFs, SL/SL-M); an ineligible scrip (ASM/GSM surveillance, F&O ban-period contracts, penny/SME filters, illiquid instruments); wrong timing (placed during live hours or a maintenance window); disclosed-quantity errors; or an RMS/validation failure on the platform side before the order reaches the exchange.

Usually a pre-release validation failure — a margin shortfall, a price-band breach, an ineligible scrip, or maintenance-window timing. Check the order’s rejection-reason text in ATS for the specific cause.

Yes — any time before it is released or executed. After the cut-off (or once it enters the auction-matching phase) modification and cancellation are blocked. During the auction’s order-matching period the exchange allows no order modification, cancellation or trade cancellation.

There is a pre-open auction from 9:00–9:15 AM and AMOs route into it. Only certain product types and order types are valid in pre-open; market orders convert to a limit at the discovered open price.

Since 8 December 2025, current-month index and stock futures have their own 9:00–9:15 AM pre-open auction (extending to next-month futures in the last five trading days before expiry). AMO collection for these stops around 8:57 AM. Market-order price protection uses the discovered equilibrium price as the reference when the normal market opens.

Options have no pre-open. They open in the continuous session at 9:15 AM, so the “open” is the first traded print, not an auction price. This is the key driver behind most “the open was above my limit but it didn’t fill” queries.

AMOs are typically accepted from after close until ~8:59 AM and the market opens around 9:00 AM. Currency derivatives carry no STT (Securities Transaction Tax).

MCX AMOs can usually be placed almost any time of day; they are batched and sent to MCX at 9:00 AM (session open). An MCX AMO placed after 9:00 AM generally goes the next day. Commodities use CTT (Commodity Transaction Tax) instead of STT.

No separate AMO fee. Standard brokerage for the segment applies, plus the usual taxes and exchange charges on execution.

No. Margin requirements are the same as a normal order in that segment and are validated at release. An AMO with insufficient margin is rejected, and there is no special leverage for being an AMO.

GTTs (Good Till Triggered orders) are evaluated against live market prices, so they trigger during market hours, not in the after-market window. To act at the open, place a dedicated AMO. Confirm exact GTT behaviour in your ATS account.

For any non-execution review, ATS pulls: the exchange order number; the exchange acknowledgement/acceptance timestamp (not just the ATS/OMS screen time); whether the instrument had a pre-open at all (options: no) and whether the order participated; the order-book/trade snapshot for the contract around 9:08–9:20 AM; the full NSE order and trade history for the order ID; and every traded price at or above your limit after the order’s acceptance time, with timestamps and quantities.

The rule is simple. If no trade at your limit printed after the order was live, it is a genuine non-execution and the order behaved correctly — a limit only executes against a counterparty at your price or better. If trades at your limit did print after the order was live and there was still zero fill, ATS escalates it internally as a possible routing/OMS issue and confirms the resolution and any remediation.