What are the upsides and downsides if one's currency exchange order is routed as an odd lot order instead of IdealPro on Interactive Brokers?

External question — Personal Finance Stack Exchange Author: Franck Dernoncourt Original post: https://money.stackexchange.com/questions/158230 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. I placed a currency exchange order on Interactive Brokers from EUR to USD. Since the amount was below 20kEUR, Interactive Brokers told me that the currency exchange order would be routed as an odd lot order instead of IdealPro. What are the upsides and downsides if one's currency exchange order is routed as an odd lot order instead of IdealPro? Message from Interactive Brokers:

External answer — Personal Finance Stack Exchange Author: Franck Dernoncourt Original post: https://money.stackexchange.com/a/158231 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Reddit user Terrigible mentioned one downside if one's currency exchange order is routed as an odd lot order instead of IdealPro on Interactive Brokers: the exchange rate is slightly below the market rate. Odd lot orders execute 1-2 pips outside the quoted spread. Reddit user major_domo pointed me to the official IBKR reference ( mirror ): Odd lot marketable limit orders will still be accepted, but they are not guaranteed execution at the inter-bank spreads afforded to IdealPro orders, and will generally be executed at slightly inferior prices ranging from 1- 2 basis points outside the IdealPro quote . Also, an Odd Lot order may take longer to get filled. The IdealPro Minimum and Maximum Forex order sizes can be found on the Interactive Brokers website.

External answer — Personal Finance Stack Exchange Author: karolba Original post: https://money.stackexchange.com/a/163618 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. From experience my experience in practice it means this: your limit order can be as close to the bid/ask inside the spread as you want, yet it will not fill unless your order touches or gets out of the spread.