Regime change: why "the strategy always worked" fails
Education only — not a recommendation to buy, sell, or hold anything.
A regime is a market climate — the typical volatility, correlation, liquidity, and policy backdrop for a period. Rules that looked great in one climate can fail in another. This page is vocabulary — not a regime-prediction service and not a strategy to trade.
The trap
Someone shows a curve from 2012–2017 and says the process"always worked." Educational response:
- What costs were included?
- Was the sample snooped? (backtesting concepts)
- Did correlations and liquidity look like today?
- How many losing streaks happened, and what size was used? (risk of ruin)
"Always" is a marketing word. Markets change.
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What can change between regimes (examples)
| Dimension | Why it matters |
|---|---|
| Volatility | Same size feels calm or violent |
| Correlation | Diversification can disappear in stress |
| Liquidity | Exits that were easy become expensive |
| Rates / inflation backdrop | Discounting and risk appetite shift |
| Microstructure / venue rules | Fills and halt behavior differ |
| Crypto cycle liquidity | Thin books punish size faster |
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Education habit
- Prefer processes you can explain without needing one magic decade.
- Journal which assumptions you are making about climate.
- Treat wire headlines as context for uncertainty, not as a regime oracle.
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Paper drill (fake money)
- Take one simple process.
- Practice it in a calm simulated tape and a jumpier one (if your mock allows volatility toggles or wider spreads).
- Compare process grade and emotional notes — not just fake P&L.
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Related
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Sentry CLEAR · Education only.