The Strategy Lifecycle

No trading strategy works forever. Markets adapt, competitors copy ideas, and the conditions that created an edge change. Professional firms treat strategies as having a lifecycle: research, launch, scaling, maturity, decay and retirement. Thinking this way helps traders size new strategies sensibly, recognise when an edge is fading and avoid both quitting too early and holding on too long.

The stages#

Incubation#

Many firms run new strategies at small size for months before committing real capital. Incubation catches data errors, execution problems and unrealistic assumptions. It also gives a first out of sample read, though usually too short to prove much statistically. See Moving From Paper to Live Trading.

Scaling up#

Increase capital in steps, checking at each stage:

• Execution costs and market impact, which grow with size. See Market Impact.
• Capacity: how much capital the strategy can handle before returns fall. See Alpha Capacity and Crowding.
• Correlation with existing strategies.

Monitoring for decay#

Statistical tools such as control charts, comparing rolling performance against the backtest distribution, help distinguish bad luck from real decay. See Monitoring Positions, P&L and Risk.

Why edges decay#

• Competition: profitable ideas attract capital, which arbitrages them away.
• Publication: research by R. David McLean and Jeffrey Pontiff (2016) found that anomaly returns fell by about a third after academic publication, on average, and more over time.
• Market structure changes: new rules, technology or participants.
• Regime changes in volatility, rates or correlations. See Structural Breaks and Regime Changes.

See Signal and Alpha Decay.

Retirement rules#

Decide in advance what will trigger reducing or stopping a strategy, for example:

1. Drawdown limits beyond a multiple of the historical maximum.
2. Rolling performance below a threshold for a set period.
3. Structural change that removes the strategy's rationale.

Pre set rules prevent emotional decisions in either direction: abandoning a good strategy in a normal drawdown or clinging to a broken one. See Discipline.

Keep a portfolio of strategies#

Because individual strategies decay at different times, many traders run several uncorrelated strategies at different lifecycle stages, continually researching replacements. See Combining Signals and Portfolio Construction.

Frequently asked questions#

What is a trading strategy lifecycle?#

The stages a strategy goes through, from research and incubation to scaling, maturity, decay and retirement.

How do I know if my strategy has stopped working?#

Compare live performance with backtest expectations using statistical ranges, watch for drawdowns beyond historical worst cases and check whether the strategy's rationale still holds.

Why do trading strategies stop working?#

Because of competition, publication of the idea, changes in market structure and shifts in market regimes.

Next, learn the most common reasons strategies fail in Why Strategies Fail.