Learn · Orders and fills
Time in force
What Day, GTC and IOC do with the part of an order that has not filled.
Last updated: 2026-09-20
How long an instruction lasts
Time in force answers a narrow question: what happens to the quantity that an order has not filled? MockTradeCity offers Day, Good till canceled (GTC) and Immediate-or-cancel (IOC). They do not replace the selected limit price, change the price priority of matching or promise a particular execution. They govern the lifetime of the unfinished instruction. The same initial match can therefore lead to different final order states depending on this setting.
Execution session is a separate choice. It defines when an order is allowed to match, while time in force defines how long it remains eligible to exist. A GTC Limit order restricted to Regular trading may wait through Overnight and Pre-market. A Day order with the same restriction has an expiry as well. These settings can explain a pending order even when its price seems close to the latest trade on the chart.
Good till canceled keeps the remainder
GTC is the default time in force for an ordinary Limit order. An eligible unfilled remainder stays open across session and date changes until it fills or is canceled, subject to the city's other market rules. Crossing midnight does not itself remove it. If its execution session is inactive, it waits for an eligible period rather than attempting to match outside the scope chosen in the order ticket.
Its reservation lasts with it. For example, the remaining 80 shares of a cash-funded purchase limited to 15 CC still require 1,200 CC of reservation. The original order may already have filled another quantity, so the remaining reservation need not equal the amount shown at first submission. Account separates filled and remaining quantities. That distinction explains why an open order continues to use resources even when you have stopped watching its company page.
Day follows a market deadline
Day does not mean a fixed twenty-four-hour timer. The city chooses the deadline from the execution-session setting, using Eastern Time. Regular-only orders expire at 4:00 p.m.; Overnight-only orders expire at 4:00 a.m.; the other supported session scopes expire at 8:00 p.m. An order submitted exactly at a cutoff uses the next applicable window. Its lifetime therefore depends on both when it is submitted and the session scope selected.
At expiry, the remaining quantity is canceled and its reserved resources are released. Earlier executions stay in place. A stop instruction is also subject to its expiry, so a trigger does not make a Day order permanent. The server handles the deadline whether or not your browser is open. Looking at the actual expiry is more precise than assuming that a change of calendar date in your own timezone ends the order.
IOC makes one immediate attempt
An IOC order matches whatever eligible quantity is immediately available, then cancels the rest. It does not mean the full quantity must fill. If 40 of 100 requested shares can execute, those 40 settle and the remaining 60 are canceled. It also cannot queue for a later session: submission outside the selected execution scope is rejected. A completed immediate attempt may therefore contain some executions or none at all.
Market orders always use IOC in the city. A Limit sale that exceeds an existing long position and would open a short also requires IOC. This avoids leaving an open short-sale remainder occupying borrowed shares and collateral indefinitely. Unused reservations are released after the immediate attempt. The ticket fixes the setting for these cases, so its availability depends on the order type and on whether the requested quantity crosses your current net position.
Where to check order lifetime in the city
The order ticket displays time in force next to the other execution settings. Account then shows the accepted state and unfinished quantity. A waiting-session message explains why an order has not started matching; an expired or canceled state explains why it no longer can. An order with fills may still end canceled, because the cancellation describes the remainder. Reading status together with quantity prevents that label from being mistaken for a reversal of every trade.
The funds history provides the corresponding reservation and release entries in City Coin. For a share sale, the reserved share quantity serves the same purpose. A cancellation request applies to what remains when processed, so a fill completed before it is still valid. The order history resolves that sequence. Matching the history to the current reservation is the way to understand committed resources without assuming that all reductions in Available CC represent losses.