{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"max-drawdown"},"result":{"entity_type":"calculator","id":"max-drawdown","calculator_id":"max-drawdown","canonical_url":"https://tttkmbb.com/investing/max-drawdown","name":"Maximum Drawdown Calculator","title":"Maximum Drawdown Calculator – Largest Peak-to-Trough Loss of an Equity Curve","category":"investing","category_name":"Investing & Real Estate","tool_name":"calculate_max_drawdown","featured_mcp_tool":false,"description":"Scans a series of portfolio or equity values in time order for the largest percentage fall from a running peak, reporting the peak and trough values and positions, whether the peak was regained, and the drawdown at the end of the series.","use_when":"You want the worst historical loss of a strategy, fund or portfolio from a list of values, or the current distance below its high-water mark.","do_not_use_when":"You need volatility-based risk (use sharpe-ratio or descriptive-statistics) or your data are period returns rather than values (convert them to a cumulative value series first). Informational only; not financial advice.","inputs":[{"name":"values","label":"Values in time order","type":"number_list","required":true,"description":"Portfolio values, prices or equity-curve points from oldest to newest (2–500 values, all greater than 0).","example":[100,120,90,110,80,130]}],"outputs":[{"name":"max_drawdown_percent","label":"Maximum drawdown","type":"number","unit":"%","decimals":2,"description":"Largest loss from a peak to a later trough, as a positive percentage of the peak."},{"name":"max_drawdown_amount","label":"Maximum drawdown (amount)","type":"number","decimals":4,"description":"peak_value − trough_value."},{"name":"peak_value","label":"Peak value","type":"number","decimals":4,"description":"Value at the start of the maximum drawdown."},{"name":"trough_value","label":"Trough value","type":"number","decimals":4,"description":"Lowest value after that peak."},{"name":"peak_index","label":"Peak index","type":"integer","decimals":0,"description":"0-based position of the peak in the list."},{"name":"trough_index","label":"Trough index","type":"integer","decimals":0,"description":"0-based position of the trough."},{"name":"drawdown_length_periods","label":"Peak-to-trough length","type":"integer","decimals":0,"description":"trough_index − peak_index."},{"name":"recovered","label":"Recovered","type":"boolean","decimals":4,"description":"True when a later value reached or exceeded the peak value."},{"name":"recovery_index","label":"Recovery index","type":"integer","decimals":0,"description":"0-based position of the first value at or above the peak after the trough (only when recovered)."},{"name":"current_drawdown_percent","label":"Current drawdown","type":"number","unit":"%","decimals":2,"description":"Fall of the last value from the running peak of the whole series, as a positive percentage (0 at a new high)."}],"input_schema":{"type":"object","properties":{"values":{"description":"Portfolio values, prices or equity-curve points from oldest to newest (2–500 values, all greater than 0).","type":"array","items":{"type":"number"},"minItems":2,"examples":[[100,120,90,110,80,130]]}},"additionalProperties":false,"required":["values"]},"output_schema":{"type":"object","properties":{"max_drawdown_percent":{"description":"Largest loss from a peak to a later trough, as a positive percentage of the peak. Unit: %.","type":"number","x-unit":"%"},"max_drawdown_amount":{"description":"peak_value − trough_value.","type":"number"},"peak_value":{"description":"Value at the start of the maximum drawdown.","type":"number"},"trough_value":{"description":"Lowest value after that peak.","type":"number"},"peak_index":{"description":"0-based position of the peak in the list.","type":"integer"},"trough_index":{"description":"0-based position of the trough.","type":"integer"},"drawdown_length_periods":{"description":"trough_index − peak_index.","type":"integer"},"recovered":{"description":"True when a later value reached or exceeded the peak value.","type":"boolean"},"recovery_index":{"description":"0-based position of the first value at or above the peak after the trough (only when recovered).","type":"integer"},"current_drawdown_percent":{"description":"Fall of the last value from the running peak of the whole series, as a positive percentage (0 at a new high). Unit: %.","type":"number","x-unit":"%"}}},"formula":"drawdown_t = (max_{s≤t} values[s] − values[t]) / max_{s≤t} values[s]; max_drawdown_percent = 100 × max_t drawdown_t; current_drawdown_percent = 100 × drawdown_n","method":"Drawdown is measured from the running maximum (high-water mark); the first drawdown that reaches the maximum depth is reported. Values must be positive for the percentage to be defined. Informational mathematics only; not financial advice.","sources":[{"name":"Wikipedia – Drawdown (economics)","url":"https://en.wikipedia.org/wiki/Drawdown_(economics)","type":"reference","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"100, 120, 90, 110, 80, 130","inputs":{"values":[100,120,90,110,80,130]},"expected":{"max_drawdown_percent":33.33,"max_drawdown_amount":40,"peak_value":120,"trough_value":80,"peak_index":1,"trough_index":4,"drawdown_length_periods":3,"recovered":true,"recovery_index":5,"current_drawdown_percent":0},"url":"https://tttkmbb.com/api/v1/calculate/max-drawdown?values=100%2C120%2C90%2C110%2C80%2C130"},{"name":"1000, 1100, 1050, 900, 950, 1000, 1080 (not recovered)","inputs":{"values":[1000,1100,1050,900,950,1000,1080]},"expected":{"max_drawdown_percent":18.18,"peak_value":1100,"trough_value":900,"peak_index":1,"trough_index":3,"recovered":false,"current_drawdown_percent":1.82},"url":"https://tttkmbb.com/api/v1/calculate/max-drawdown?values=1000%2C1100%2C1050%2C900%2C950%2C1000%2C1080"}],"faq":[{"q":"Why is the drawdown reported as a positive number?","a":"It is the size of the loss from the peak; a 33.33 % drawdown means the value fell to 66.67 % of its peak. A gain of 50 % is then needed to recover."},{"q":"Can I enter returns instead of values?","a":"Convert them first: start at 100 and multiply by (1 + return) each period to get a value series, then enter those values."}],"tags":["maximum drawdown","max drawdown","peak to trough","equity curve","downside risk","high water mark"],"related":[{"calculator_id":"sharpe-ratio","reason":"Volatility-based risk-adjusted return."},{"calculator_id":"descriptive-statistics","reason":"Mean and standard deviation of the same series."},{"calculator_id":"percentage-change","reason":"Gain needed to recover from a given loss."}],"links":{"html":"https://tttkmbb.com/investing/max-drawdown","markdown":"https://tttkmbb.com/investing/max-drawdown.md","json":"https://tttkmbb.com/investing/max-drawdown.json","api":"https://tttkmbb.com/api/v1/calculate/max-drawdown","schema":"https://tttkmbb.com/api/v1/calculators/max-drawdown","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T03:45:03Z","next_actions":[{"tool":"run_calculator","calculator_id":"max-drawdown","reason":"Run Maximum Drawdown Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/investing/max-drawdown.md"}}