Definition of 'Decimalization'
A system where security prices are quoted using a decimal format rather than fractions. For example, this is a decimal trading quote: $34.25. Using fractions, the same quote would appear as $34 1/4. The U.S. Securities and Exchange Commission (SEC) ordered all stock markets within the U.S. to convert to decimalization by April 9, 2001, and all price quotes since appear in the decimal trading format.
Before 2001, markets in the United States utilized fractions in price quotes. The switch was made to decimalization to conform to standard international practices and to make it easier for investors to interpret and react to changing price quotes.
Investopedia explains 'Decimalization'
Decimalization has led to tighter spreads because of the corresponding smaller price increments and movements. For example, prior to decimalization, one-sixteenth (1/16) of one dollar was the smallest price movement that could be represented in a price quote (this is approximately six cents, or $0.0625). With decimalization, the minimum price movement is now one cent, or $0.01, providing a greater number of price levels, and allowing for tighter spreads between the bid and the ask levels for trading instruments.