Good-til-canceled (GTC) order

What it means

A GTC instruction keeps an unfilled order open beyond the trading day on which it was entered. It is a time-in-force choice: it determines how long an order may remain eligible for execution, not the price at which it executes. A GTC order can be paired with a limit order or another order type if the broker supports that combination.

“Until canceled” does not necessarily mean indefinitely. Brokers and trading venues can impose expiration periods, and an order can cease to be active for other reasons under their rules. Check the expiration date and status shown by your broker rather than assuming an old order is still working. A trading halt can also prevent execution while the halt is in effect.

How it is calculated

GTC is an instruction, not a financial quantity, so there is no GTC-specific price or return formula. To track how much of an order remains after fills, use remaining shares = original order shares − cumulative filled shares.

• Remaining shares: shares still open, measured in shares, if the order remains active.
• Original order shares: shares requested when the order was submitted, measured in shares.
• Cumulative filled shares: shares executed so far across all fills, measured in shares.

A partial fill reduces the remaining quantity; it does not automatically cancel it. Execution and expiration depend on the order terms and broker or venue rules. For a limit order, GTC does not guarantee that the limit price will become available or that any shares will fill.

Worked example

Suppose, hypothetically, an investor submits a GTC limit order for 100 shares of a stock at US$50 per share. The limit price sets the highest price the investor will pay per share on this buy order; GTC sets how long the order can remain open, subject to the broker’s expiration policy.

1. On the first trading day, 30 shares execute at US$50. The calculation is 100 shares − 30 shares = 70 shares remaining.
2. On the next trading day, another 20 shares execute at US$49.80. Cumulative fills are 50 shares, leaving 100 shares − 50 shares = 50 shares.
3. If the investor cancels the remaining order before any further fill, those 50 shares do not execute under that order. Alternatively, the open portion could later fill or reach the broker’s expiration date.

The two fills have a hypothetical share-weighted average price of (30 × US$50 + 20 × US$49.80) ÷ 50 = US$49.92 per share, excluding fees. That average describes the 50 executed shares, not the 50 still open.

Why it matters before you trade

An order left open can execute on a later day when the investor is no longer watching it. News, earnings, a gap at the open, or a change in available liquidity may alter the context in which the original order was entered. A limit price constrains the execution price of a limit order, but it does not eliminate the risk that the reason for placing the order has changed.

Before submitting an order, distinguish its time-in-force from its order type. Check the broker’s GTC expiration policy, whether the order can fill partially, and how the broker handles corporate actions such as stock splits or dividends. An unfilled GTC order is not a position, but it may become one later if it executes.

How PreTrAIde uses it

PreTrAIde provides pre-trade analysis of a stock basket whose lines include a side, quantity, and execution conditions. Its analysis returns GO, NO-GO, or MODIFY verdicts, risk assessments, and suggested execution strategies before an order is placed. Those verdicts are decision support, not instructions to submit an order.

The product facts do not specify a GTC-specific calculation or state that PreTrAIde tracks an order’s time-in-force after submission. A pre-trade check can help put quantity, liquidity, estimated spread, market impact, and execution conditions in context; the investor must confirm the actual GTC setting and order status with their broker. PreTrAIde does not receive, transmit, or execute orders.

Common mistakes

• Treating GTC as permanent: A broker or venue may set an expiration date.
• Confusing GTC with a price instruction: GTC says how long an order remains eligible; a limit price specifies a price boundary.
• Assuming a full fill: An order can fill in parts or remain unfilled.
• Forgetting the open balance: A partially filled order may still have shares eligible to execute later.
• Overlooking changed circumstances: Review open orders when news, corporate actions, or your intended position changes.