Log scale
A logarithmic (log) price scale spaces equal percentage steps equally: every doubling, from 10,000 to 20,000 or from 40,000 to 80,000, is the same height on the chart.
A log scale shows what happened to your money, because profit and loss are percentages. It matters once the highest price on the chart is about twice the lowest: on Bitcoin that is typical for a one-year chart (2.96 times from bottom to top) and not for a day (1.04 times). Horizontal levels sit at the same price on both scales.
Learn more: linear or log chart.