broken line graph meaning in English

折线统计图
折线图

There is one chart on fund net every day , with such as : quantify core ( 360001 ) broken line graph in stating an intention , the watch has 2 lines is black , one is gules , consult ace now : do they represent these 2 lines respectively what
天天基金网上有一图表，用诸如：量化核心（ 360001 ）折线图表述图中有二条线一条是黑色的，一条是红色的，现请教高手：这二条线它们分别代表什么？