 Visualizing market information has changed over the years from the early days of tape reading and the bucket shops of the Jesse Livermore era, onto simple line charts, candlesticks, volume bars, footprint charts and the DOM. Many of these changes were brought about by the evolution of technology. We now have faster and more powerful computer systems than ever before. This creates new opportunities for data visualization. Many see liquidity heatmaps as just the next step forward in visualizing real-time market information and order flow.