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Portfolio Construction Across Multiple Strategies
Portfolio construction is the discipline of combining several trading strategies into one coherent book, so the whole is more stable than any single strategy on its own. This lesson assumes you've already worked through position sizing and risk-per-trade (Module 17) and drawdown management (Module 18) — portfolio construction is where those single-strategy skills get stitched together into something you can run for years, not just weeks.
Why Combine Strategies at All
A single strategy, however good, has a return stream with its own rhythm of winning and losing spells. Combine it with a second strategy that tends to win when the first is losing, and the combined equity curve is smoother than either alone — same underlying edge, less emotional and financial strain.
Reasons traders build multi-strategy portfolios:
- Smoother equity curve — fewer prolonged flat or losing periods across the whole book
- Regime coverage — a trend-following system and a mean-reversion system tend to take turns performing well
- Capacity — spreading risk across setups avoids over-concentrating size in one edge
- Resilience to broker or platform issues — if one strategy needs a specific execution environment, the others aren't dependent on it
The trap is assuming that running more strategies automatically means more diversification. It doesn't. Two momentum strategies on EUR/USD and GBP/USD will often move together, because both currencies react to the same dollar-driven news. Real diversification comes from return correlation, not from strategy count.
Measuring Correlation Properly
Don't eyeball this — calculate it. Pull the periodic (daily or weekly) return series for each strategy, not the raw trade list, and run a correlation matrix in a spreadsheet.
Rules of thumb:
- Below 0.3 — genuinely diversifying, good portfolio candidates
- 0.3 to 0.6 — some overlap, still useful but size accordingly
- Above 0.6-0.7 — treat as effectively one strategy for risk-budgeting purposes
Correlation is not fixed. It tends to rise sharply in stressed markets — exactly when you most need diversification — so recalculate it periodically rather than trusting a single backtest figure. A pair of strategies that looked uncorrelated over a calm year can move in lockstep during a volatility spike.
Allocating Capital by Risk, Not by Feel
Once you know which strategies genuinely diversify each other, the next question is how much capital or risk each one gets. Equal lot sizes across strategies is a common mistake — a low-volatility carry-style approach and a high-volatility breakout system are not equivalent just because they use the same lot size.
A more robust approach:
1. Estimate each strategy's expected volatility (standard deviation of returns) from its track record or backtest 2. Size allocations so each strategy contributes a similar *amount of risk* to the portfolio, not a similar amount of capital 3. Adjust for correlation — two moderately correlated strategies shouldn't each get a full-size allocation, or you're doubling up on the same risk 4. Revisit allocations on a fixed schedule (monthly or quarterly), not whenever a strategy has a bad week
This is the same risk-per-trade thinking from Module 17, just applied one level up — from position to strategy to portfolio.
Setting a Portfolio-Level Drawdown Budget
Each strategy should already have its own drawdown limit from Module 18. Portfolio construction adds a layer above that: a combined drawdown budget for the whole book.
- Decide the maximum combined drawdown you're prepared to accept before you start, in writing
- Split that budget across strategies in proportion to their allocation, not equally
- Define in advance what happens when a single strategy hits its individual limit — pause it, don't average down or "let it run" out of hope
- Define what happens when the *combined* book hits its limit — this usually means pausing everything and reviewing, not just the worst performer
This turns a stressful, emotional decision into a mechanical rule you set when you're calm, not when you're three weeks into a losing streak.
Rebalancing and Cutting Underperformers
Markets rotate. A strategy that carried the portfolio last year may be dead weight this year. Rebalancing keeps the mix honest.
A workable rebalancing routine:
| Trigger | Action | |---|---| | Scheduled review (monthly/quarterly) | Recalculate correlations and volatility, adjust allocations | | Strategy hits its own drawdown limit | Pause that strategy, don't resize others to compensate emotionally | | Strategy correlation rises sharply | Reduce combined allocation to the correlated pair | | Strategy underperforms its backtest for a defined period | Flag for review — not automatic removal, but scrutiny |
Write these triggers down before you need them. A rebalancing rule invented mid-drawdown is rarely a good one.
Execution and Cost Considerations Across Strategies
Every strategy in the portfolio still incurs its own trading costs, and these can behave very differently at scale. A high-frequency scalping strategy is far more sensitive to spread and commission than a monthly swing strategy — the same broker setup that's fine for one can quietly erode the other.
Practical points:
- Check execution suitability per strategy, not just per account — for instance, a scalping system may sit better on Pepperstone's raw-spread MetaTrader servers, while a slower swing approach might run comfortably on IG's own platform
- Re-audit costs whenever you materially change strategy mix or size, using PipTax's [cost tool](/audit.html)
- Compare current broker offerings for each strategy's execution needs on the [brokers page](/brokers/index.html) — don't assume one broker is optimal for everything
- Remember swap costs compound differently across strategies holding different average durations; check current rates via the [rates page](/rates.html) rather than relying on memory
Never assume a spread or commission figure — always confirm live numbers before sizing a new strategy into the book.
Bringing It Together
Good portfolio construction isn't about running as many strategies as possible — it's about deliberately combining a handful of genuinely diversifying approaches, sizing them by risk rather than feel, and having written rules for rebalancing and cutting losers before you need them. Trading remains risky, most retail accounts still lose money, and no portfolio structure removes that risk — it only manages it more deliberately. For the full sequence of ideas this lesson builds on, revisit the earlier modules in the [PipTax FX Trading School](/school/index.html), and consult PipTax's [methodology](/methodology.html) for how the cost tool's figures are calculated.
Key takeaways
- Portfolio construction is about combining strategies with low correlation, not just stacking more trade ideas on top of each other
- Allocate capital by risk contribution, not equal lot sizes — a volatile strategy needs a smaller slice of the book
- Correlation between strategies must be measured on returns, not on the instruments they trade
- Set a portfolio-level drawdown budget and cut allocation to underperforming strategies mechanically, not emotionally
- Rebalancing rules should be written down in advance, including what triggers a strategy being paused entirely
- Every strategy in the portfolio still needs its own cost audit — spreads, commissions and swaps compound differently at scale
Frequently asked questions
- How many strategies should a retail trader run at once?
- There's no fixed number, but most retail traders get diminishing returns beyond three to five strategies because monitoring, correlation-checking and cost tracking all get harder. Start with two genuinely different strategies — for example a trend system and a mean-reversion system — before adding more.
- Is running multiple strategies the same as diversification?
- Not automatically. Two strategies trading the same pairs in the same direction at the same time are not diversified, even if the entry rules look different. Diversification depends on the correlation of their returns, which you have to measure, not assume.
- How do I measure correlation between my own strategies?
- Export the daily or weekly return series (not the raw trades) for each strategy from your journal or backtest, then calculate the correlation coefficient between each pair in a spreadsheet. Anything consistently above roughly 0.6-0.7 should be treated as effectively one strategy for risk purposes.
- Should I use the same broker for every strategy in the portfolio?
- Not necessarily. Execution needs differ by strategy — a scalping system may need Pepperstone's raw-spread MetaTrader servers, while a longer-term swing strategy might run fine on IG's own platform. Check current costs for each use case on the cost tool before deciding.
- What's a sensible portfolio-level drawdown limit?
- That depends on your overall risk tolerance and account size, and this isn't investment advice — but many traders set a hard portfolio stop well below their per-strategy limits, so no single bad month across all strategies at once can do serious damage. Define the number before you start, not during a losing streak.