Day trading charts can be based upon several different criteria, with the most popular being time, ticks (number of trades), volume (number of contracts), and price range. All fourtypes of charts use the same market information (price, volume, etc.), but they display the information slightly differently.
Volume
Charts based upon volume make a new price bar (or candlestick, line, etc.) every time a specific number of contracts have been traded. This is different from tick charts because a single trade can consist of several contracts. For example, a single trade for 10 contracts would be 1 tick on a tick chart, but would be 10 contracts on a volume chart. Popular volume charts are 500 contracts and 1000 contracts, but any number of contracts might be suitable depending upon the market being traded. Volume charts also adjust to the market, and make price bars less often when the market is moving slowly, as there are less contracts being traded.
