Some embodiments of the present invention include an apparatus for displaying line charts with responsive line thickness using a display screen of a mobile computing system and include a processor, and one or more stored sequences of instructions which, when executed by the processor, cause the processor to receive a request to display a line chart on a display screen of a mobile computing system with the line chart having multiple line segments, determine density of information to be displayed with the line chart, and display the line chart with thickness of lines of the line chart corresponding to the determined density of information. The thickness of the line segments of the line chart is relatively thinner when the line chart includes higher density of information and relatively thicker when the line chart includes lower density of information.