Stock Price Cycles: Trendline Analysis
This calculator conducts a detailed analysis of repeated price upsides and downsides (price cycles) and their trendlines for any stock, exchange-traded fund (ETF) or mutual fund supported by Alpha Vantage. Indexes are not supported.
The Monthly Return Period gives a broad overview of the price cycles while the Weekly Return Period gives more detail.
This calculator is not intended as a short-term trading tool so daily prices are not included.
Many investors could benefit from examining where current prices stand with respect to peak and trough prices if they intend to buy or sell their stock.
Log Adjusted Closing Prices (Splits & Dividends) are particularly useful for multi-year periods of analysis.
This calculator was generated in part by Gemini-3.
Linear Trendline Statistics
| Trendline Parameter & Metrics Summary | |
|---|---|
| Linear Regression Slope (m): | 3.967387 per monthly interval |
| Y-Intercept (b): | $40.55 |
| Initial Trendline Value (2021-08-31): | $40.55 |
| Final Trendline Value (2026-08-19): | $278.60 |
| Current Price Deviation from Trendline (%): | +67.42% |
| Total Trendline Change: | +$238.04 |
| Total Trendline Growth (%): | +586.96% |
| Prices Above Trendline: | 20 (32.79%) |
| Prices Below Trendline: | 41 (67.21%) |
| Max Deviation Above Trendline (%): | +201.90% |
| Max Deviation Below Trendline (%): | -54.75% |
| Average Deviation Above Trendline (%): | +77.19% |
| Average Deviation Below Trendline (%): | -23.66% |