What does the semi-logarithmic scale depict in relation to price changes?

The semi-logarithmic scale is specifically designed to represent percentage changes in price rather than absolute dollar amounts. In this type of chart, the price axis is plotted on a logarithmic scale, allowing for an equal representation of percentage movements across different price levels. This means that a price change from $10 to $20 (a 100% increase) takes up the same vertical space as a change from $100 to $200 (also a 100% increase), even though the absolute dollar amounts differ.

This approach is particularly useful in financial analysis because it helps visualize performance over time in a way that evenly represents growth in percentage terms, regardless of the absolute price levels involved. Traders and analysts can better interpret long-term trends and identify more significant percentage-driven movements without being skewed by the nominal price levels.

By focusing on percentage changes, the semi-logarithmic scale enables clearer comparisons across a wider range of price data, which is crucial in technical analysis.