On Upstox, when you choose IOC (Immediate or Cancel) as the order validity, it will only be executed if the required securities are available immediately. If not, your order will be canceled. There are instances where securities might be partially available, leading to the execution of a partial order.

As market prices for stocks fluctuate constantly, investors often use IOC orders when placing large orders to avoid having their order filled at multiple prices.

If you prefer to avoid order cancellation, you can select the DAY option under validity. When you choose DAY, your order remains open for the entire day it is entered. It will only be automatically canceled if it doesn't get executed on that day.

For more information on how to place an order on Upstox, click here.