What is the odd lot NBBO?
The odd lot NBBO (National Best Bid and Offer) displays the best odd lot bid and best odd lot offer priced inside the standard (round lot) NBBO. It represents better prices available in the market from orders that are smaller than a round lot.
What is an odd lot?
An odd lot is an order for a quantity smaller than the round lot size assigned to that stock. Round lot sizes are determined by each stock's average closing price under SEC Regulation NMS.
Why am I seeing this now?
SEC Regulation NMS requires exchanges to publish odd lot NBBO data alongside the existing round lot NBBO starting April 27, 2026. Previously, this data was only available through premium proprietary exchange feeds. It is now required by the SEC to be disseminated by the SIPs (Securities Information Processors) and made available to all investors.
Does the odd lot NBBO replace the regular NBBO?
No. The odd lot NBBO supplements the existing round lot NBBO. The standard NBBO continues to be displayed by default. Odd lot data is shown in addition when it is equal to or better than the round lot NBBO.
Are odd lot quotes protected?
No. Odd lot quotes are not protected quotations under Regulation NMS. There is no guarantee of execution at these prices.
When is odd lot data displayed?
Odd lot data is displayed when the odd lot bid or offer is equal to or better than the corresponding round lot NBBO. If the odd lot price is worse, it is not shown. Odd lot data can also be single-sided — for example, only the bid side may have a better odd lot price.
What does "None" mean in the odd lot popup?
"None" means there is no odd lot data available for that side (bid or offer). This can happen when no odd lot orders are priced inside the round lot NBBO.
What information is shown in the odd lot popup?
The popup displays the odd lot price, size, and contributing exchanges for each side (bid and offer) where odd lot data is available.
Where can I see the odd lot NBBO?
Odd lot NBBO data is available in the order entry screen on all IBKR platforms.