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Retirement Planner · Track 2
G9 of 9 — Input guides

Crisis stress testing

The crisis scenarios let you ask the hardest question in retirement planning: what happens to my plan if markets crash early in retirement? Not on average — but in that specific bad sequence of events.

Three distinct crisis types — different shocks, different timings 2008 GFC −57% drawdown / 17mo Global contagion Shock timing: Y0 (at retirement) 2022 Rate Shock −25% drawdown / 12mo Rate-driven bond + equity fall Shock timing: Y12 Black Monday 1987 −34% drawdown / 3mo Sharp crash, fast recovery Shock timing: Y21 Three different crash types at different retirement years — tests plan across the full horizon
The historical presets
1
Black Thursday 1929 — Great Depression

Markets fell ~85% from peak over 3 years, with recovery taking over a decade. The longest and deepest crash in modern financial history. Use this to test the absolute worst documented scenario.

2
1970s Stagflation

Prolonged high inflation combined with low growth. Uniquely dangerous because it damages both equities and bonds simultaneously, while also eroding the real value of inflation-linked spending.

Stagflation is the scenario most likely to expose plans with fully inflation-linked expenses. Both the portfolio returns and the real cost of spending worsen at the same time.
3
Black Monday 1987, Dot-com 2000, 2008 GFC, 2022 Rate Shock, Covid 2020

Five distinct modern crash patterns: a single-day shock (1987, −34%), a slow tech-led bear market (2000, −49%), a global financial contagion (2008 GFC, −57% / 17 months), a rate-driven simultaneous bond and equity fall (2022, −25%), and a sharp crash with rapid recovery (Covid 2020). Each tests a different dimension of plan resilience.

How to configure a crisis
4
Add crashes and read the parameter matrix

Go to the Crisis scenarios tab and click + Add crash. Select an Event preset to load historical parameters. Six parameters are configurable per crash: run-up duration and gain, peak drawdown, duration to trough, recovery duration, shock timing (retirement year), and severity scale. The Shock sequence preview chart plots all crashes as labelled bands (C1, C2, C3) on an illustrative £100 portfolio — here, 2008 GFC at Y0, 2022 Rate Shock at Y12, and Black Monday 1987 at Y21.

Crisis scenarios tab showing shock sequence preview chart with C1 (2008 GFC), C2 (2022 Rate Shock) and C3 (Black Monday 1987) plotted, plus full parameter matrix for all three crashes
Mixing different crash types at different retirement years gives a more realistic stress test than repeating the same event. The 2022 Rate Shock is particularly relevant for balanced or bond-heavy portfolios — it hits both asset classes simultaneously.
5
Set severity and shock timing

Severity scale (0–100%) scales all parameters proportionally. Shock timing is the retirement year the crash begins. Y0 = at retirement is maximally damaging — the portfolio is at its peak with no cushion. The same crash at Y0 versus Y10 can produce a 15–20 percentage point difference in success probability due to sequence-of-returns risk.

The Total window row shows the combined crash footprint per slot. A 122-month window (C1 in the example) is 10 years — the engine will warn if windows approach or exceed the retirement horizon.
Reading a crisis result
6
Portfolio value fan — how the crash compresses outcomes

The portfolio fan chart shows the P10–P90 range across the full retirement horizon. Crisis windows appear as coloured bands (C1 run-up, C1 crash, C1 recover, C2 run-up etc.) directly on the chart. During the crash phases the fan compresses and the P50 median path drops. In this 3-crash scenario the median ends at roughly £350k — still surviving, but significantly below the no-crisis baseline. The P10 (worst 10% of paths) approaches zero late in retirement.

Portfolio value percentile fan chart showing P10-P90 band and P50 median declining through the three crisis windows C1 C2 C3 across the 40-year retirement horizon
7
Cash balance — the buffer band in action

The cash balance chart (P50 path) shows the buffer cycling through its sawtooth pattern — topping up from the portfolio, then depleting as expenses are paid. Each crash window briefly interrupts the cycle. The chart shows the buffer staying positive through all three crashes on the median path, with the tooltip confirming a cash balance of −£142k late in retirement where the P50 path eventually tips into shortfall territory.

Cash balance post-retirement chart showing sawtooth buffer pattern with green cash balance bands and red shortfall shading appearing late in the horizon, with C1 C2 C3 crisis windows visible
The cash buffer strategy (S6) is visible here: the sawtooth pattern shows the buffer refilling from the portfolio each time it approaches the floor, rather than drawing continuously. This is the shock absorber in action — during crash windows the portfolio is not sold, giving markets time to recover.
8
Cumulative success probability — reading the decline

The success probability chart starts at 100% and declines as the horizon extends. The coloured background bands show safe (green >95%), caution (amber 80–95%), and concern (red <80%) zones. In this scenario the plan stays above 95% through the first two crash windows, enters caution territory around age 68, and continues declining to roughly 45% by age 74. The tooltip shows success probability at age 60 is still 99.9% — the damage accumulates gradually over the full horizon.

Cumulative success probability chart showing probability at 100% through pre-retirement, tooltip showing 99.9% at age 60, then declining through the crisis windows to around 45% by age 74
Use the What-if tab to compare with and without crises. Save the no-crisis run as baseline, add the crashes, run again. The delta in success probability is your crisis vulnerability number.
Track 2 · G9 of 9