Unit of trading

When you buy stocks, bonds, options and commodities futures, it's typical to buy in a particular volume or a particular dollar value, called a round lot or a unit of trading.

For example, stocks are usually traded in lots of 100 shares, or multiples of 100 shares, and bonds in multiples of $1,000. For some preferred stocks, known as ten-share traders, the unit of trading is ten shares.

Any variation from the standard unit of trading is known as an odd lot.