Odd Lot
Any order for fewer than 100 shares (a round lot). Odd lots are executed differently by some exchanges and historically excluded from certain quotes.
An odd lot is an order for fewer than the standard round lot of 100 shares. Orders for exactly 100 shares or multiples thereof are round lots; everything in between is a mixed lot.
Historically, odd lots were excluded from NBBO calculations on some exchanges, but SEC rule changes have increased their transparency. With commission-free trading and fractional shares widening access, odd lot activity has surged — making odd lot data a useful indicator of retail sentiment in some analyses.
For most retail traders today, odd lot mechanics are invisible: brokers handle routing seamlessly regardless of share count.
Related Terms
Limit Order
An order to buy or sell only at a specified price or better. Guarantees price but not execution.
BeginnerMarket Order
An order to buy or sell immediately at the best available price. Guarantees execution but not the fill price.
BeginnerOrder Book
The real-time record of all outstanding buy and sell limit orders for an asset, organized by price level.
Beginner