ShieldPUBLIC INFORMATION / TRANSPARENT METHODS
Understand a historical drawdown calculation
Historical charts describe a selected past dataset. This example shows how to reproduce the numbers instead of treating a chart as a forecast.
Drawdown uses an earlier peak
The retained S&P 500 price-index observations use a prior peak close of 1,565.15 on October 9, 2007 and a later trough close of 676.53 on March 9, 2009. The change is (676.53 / 1,565.15 − 1) × 100 = approximately −56.78%.
The peak must precede the trough. Taking a period's highest and lowest values without considering their order can describe a fall that never actually occurred.
Recovery depends on the window
The retained series first closes at or above that earlier peak on March 28, 2013. A window ending earlier correctly reports that recovery is not observed in view. It does not assume a future recovery or replace an unavailable date with zero days. Durations use calendar days rather than trading sessions.
Aligning events to 100
For each reference date, select the last positive close strictly before it, at most seven calendar days earlier. Divide a later value by that close and multiply by 100. This aligns scale while retaining actual dates and observations; it does not make crises equal in cause, severity, duration or policy response.
What is excluded
Price indices exclude reinvested dividends, fees, taxes and trading costs. Some stress series are weekly while prices can be daily. No zero is inserted for a missing day. Historical data may include later revisions and events are selected with hindsight.
Reproduce the result
Open Crisis history, choose the financial-crisis episode and S&P 500, inspect the range and download the CSV. The retained snapshot was built on November 1, 2026; each series lists its source. Recalculate the running peak, each later decline and the first close regaining that peak. Changing the window can change the answer.
This is a descriptive calculation, not a model of the probability or timing of another crisis. See the limits or report a dated source mismatch.