Three Ways to Be a Systematic Trader
Reading Notes · Systematic Trading — Part 4
Here's something Carver slips in almost offhandedly near the end of Systematic Trading: a retired teacher with a Vanguard account and a quarterly rebalancing calendar is, in the essential sense, practising systematic trading. The futures fund manager with six screens and seventeen automated rules is doing the same thing — just with more complexity layered on top.
Part Four is where the book stops being about theory and starts being about you. If you've read Part 1, Part 2, and Part 3, you've absorbed Carver's case for why systematic beats discretionary, the mathematical architecture of forecasts and position sizing, and the full technical framework. Chapters 13 through 15 ask a narrower question: given all that, where do you fit?
One framing before we go further: nothing in this post, and nothing in Carver's book, constitutes investment advice. Every framework here is descriptive — a way of thinking about how systematic approaches work — not a prescription for what any specific person should do with their money. Carver makes this explicit throughout, and so do I.
Most of the Benefit, Without the Bloomberg Terminal
Chapter 14 — the Asset Allocating Investor — is the one I'd hand to someone who just asked "should I be doing this?" It describes the simplest possible instantiation of systematic discipline: a portfolio of diversified ETFs, rules-based rebalancing, no borrowed capital, no futures.
The core insight Carver builds Chapter 14 around is that diversification is the only reliable free lunch, and you don't need derivatives to access it. An investor holding SPY (US equities), TLT (long-duration Treasuries), GLD (gold), and EFA (international developed equities) in roughly equal volatility-weighted allocations has already captured most of the structural benefit of the more complex systems described elsewhere in the book.
What makes it "systematic" isn't the instruments — it's the rules. Specifically:
- Rebalancing triggers are pre-specified, not reactive. You rebalance when allocations drift beyond a set threshold (Carver suggests something in the range of ±5–10% from target), not when you feel anxious about a news cycle.
- Instrument selection is done once, deliberately. You choose your ETF universe, document your reasoning, and don't revisit it because you read a compelling argument for a hot new sector fund.
- There is no market timing. The asset allocating investor makes no forecast about whether equities will outperform bonds next quarter. The system doesn't require that forecast to work.
The rebalancing rule is more powerful than it first appears. In a falling equity market, it forces purchases of equities and sales of whatever held up — the mechanical opposite of panic selling. In a rally, it reverses. This is disciplined contrarianism implemented as policy rather than character, which is a much more reliable form.
Carver walks through the volatility targeting calculation in Chapter 14: sizing each ETF so its contribution to total portfolio volatility is roughly equal, rather than allocating equal capital. In practice, this tends to overweight bonds relative to equities compared to a naive 60/40, because bonds are less volatile per dollar. Whether that's appropriate for any specific investor depends on time horizon, drawdown tolerance, and existing liabilities — all things Carver explicitly defers to the individual.
The risk he doesn't soften: long-only ETF portfolios can and do suffer substantial drawdowns. A volatility-targeted four-asset portfolio lost significantly in 2022 as equities and bonds fell simultaneously — a scenario that confounds naive diversification assumptions. Systematic rules don't prevent losses. They prevent the additional losses that come from abandoning a sensible allocation at exactly the wrong moment.
Capital requirements for this archetype are meaningful but not prohibitive. You need enough capital that fractional-share rounding doesn't distort your allocations, and enough patience to survive a sustained drawdown without abandoning the rules. The minimum isn't a number — it's a commitment.
Rules for Sizing, Judgment for Picking
Chapter 13 introduces the Semi-Automatic Trader, and the distinction is subtle but important: this archetype applies the full systematic framework to position management while retaining discretion over which instruments to trade.
In practice: you decide (with qualitative judgment) that you want exposure to crude oil futures. The systematic rules then take over — how large a position, when to adjust it, how much total volatility it contributes to your portfolio. The "what" is discretionary; the "how much and when" is systematic.
Carver's argument for this hybrid approach is specific to where cognitive biases do the most damage. His case across Parts One and Two is that discretionary traders fail most severely in two places: sizing decisions (overconfidence leads to oversizing winners) and exit decisions (loss aversion leads to holding losers too long). Those are exactly the places the systematic rules govern. The instrument selection — which futures contract, which market — is less prone to those particular failure modes.
The Chapter 13 worked example is instructive. Carver takes a trader who has identified five futures markets they want to trade based on their own research, then demonstrates how to calculate the correct volatility-targeted size for each, the total portfolio risk, the rebalancing rules, and the position buffer. The trader's judgment determines the menu; the spreadsheet determines the serving sizes.
This is probably the most realistic archetype for someone who wants to apply systematic discipline to genuine market research rather than abandoning discretion entirely. The risk, which Carver names clearly: instrument selection remains a source of performance drag if it isn't itself disciplined. You haven't eliminated human bias from the process; you've contained it to one decision point. Whether that containment is sufficient depends on how honest you're willing to be about why you're selecting specific instruments at specific times.
Capital requirements here are driven by futures margins — similar to the Staunch Systems Trader but somewhat reduced if you're running a smaller, more concentrated portfolio. Time commitment is moderate: initial instrument research, then ongoing application of the systematic rules. Carver estimates a few hours per month for a small portfolio.
The Full Stack: Where the Numbers Get Honest
Chapter 15 describes the Staunch Systems Trader, and this is where Carver is most candid about barriers to entry.
This archetype operates a fully automated system: multiple futures markets, multiple forecasting rules (typically several EWMAC variants at different speeds plus Carry), automated signal generation, automated position sizing, and — if built correctly — minimal human intervention during operation. The position sizing formula from Part Three applies simultaneously across all instruments. The Instrument Diversification Multiplier credits you for holding uncorrelated positions. The Forecast Diversification Multiplier rewards combining multiple rules: Carver's calibration tables show FDM values of ~1.35 for six forecasts, meaning a diversified system can size positions 35% larger at the same volatility budget.
The constraints Carver refuses to minimise:
Capital. For a meaningful futures portfolio — four to six instruments with real diversification — his calculations suggest you need roughly $150,000–$250,000 at a 25% annual volatility target to hold even one contract in each instrument without distorting the position sizing logic. The E-mini S&P 500 alone requires approximately $20,000–$30,000 of capital per contract at that target. Undercapitalised accounts face a hard choice: sacrifice diversification (fewer instruments) or sacrifice proper sizing. Carver's explicit recommendation is to sacrifice diversification first — set your IDM to 1.0 and accept the concentration rather than the leverage distortion.
Complexity. Building and maintaining an automated system is genuine software engineering: continuous futures construction, price data cleaning, roll calendar management, position reconciliation, live monitoring. Carver spent years doing this professionally at AHL. He does not pretend the technical barrier is low.
The no-override rule. In Chapter 15, Carver returns to what is probably the hardest part operationally: the system will sometimes generate positions that feel wrong. It will hold losing trades longer than feels comfortable. It will enter positions when the news is alarming. The rule is absolute — you override the system to fix bugs in the rules, never to second-guess the current signal. The discipline required to enforce this alone, without an institutional risk committee keeping you honest, is psychologically demanding in ways that backtesting cannot capture.
The chapter is aspirational, but Carver earns that aspiration by being completely honest about what it costs.
Which Trader Are You, Really?
The comparison Carver's three archetypes invite isn't really about sophistication. It's about an honest accounting of three variables: time, capital, and the willingness to accept mechanical discipline over long periods.
| Asset Allocating | Semi-Automatic | Staunch Systems | |
|---|---|---|---|
| Instruments | ETFs (long-only) | Futures (selected) | Futures (multiple, systematic) |
| Capital minimum | Accessible | Medium (futures margin) | High ($150k+) |
| Time commitment | Hours per quarter | Hours per month | Hours per week (to build) |
| Discretion retained | Instrument selection (initial) | Instrument selection (ongoing) | None (rule changes only) |
| Complexity | Low | Medium | High |
There is no correct answer on this table. The asset allocating investor is not doing a simplified version of what the staunch systems trader does — they are doing the same essential thing (pre-specified rules, no in-flight overrides) at a scale appropriate for their situation.
The asset allocating chapter is the most immediately actionable path for most readers. A disciplined ETF portfolio with volatility-weighted allocations and rules-based rebalancing captures the essential systematic benefit — behavioural consistency under pressure, forced contrarianism, no market timing — without futures accounts, automated systems, or the capital requirements of Chapter 15. For someone working through this framework seriously, the question isn't whether to aspire to a full automated futures system someday. It's whether the additional complexity is justified relative to the already-substantial benefit available at the simpler end.
What the Epilogue Actually Says
Carver's Epilogue is brief and, in the best sense, deflating. He does not close with triumphalism about systematic trading's superiority or predictions about future returns.
He acknowledges directly that trend-following alpha may be eroding as more capital pursues it. He thinks it remains positive; he does not claim certainty. He states plainly that no systematic system prevents large drawdowns — systematic discipline is about surviving them behaviourally, not about eliminating them statistically. He notes that the cognitive benefits of systematic trading (reduced emotional interference, consistent application of rules) are real and measurable, while the performance benefits over a well-executed discretionary approach are harder to demonstrate and depend heavily on the practitioner.
He ends, essentially, by saying: the value of a systematic approach is not that it produces superior returns, but that it removes the worst version of yourself from the decision loop. That's honest. That's also as good a reason as I've found in the trading literature to take this framework seriously.
Whether you end up managing a four-ETF rebalancing portfolio or building a multi-instrument automated futures system, Carver's argument is the same: define the rules before the market opens, execute them without interference, and change them only when you have a quantified reason — never in response to recent performance. The archetype you choose determines the complexity. The discipline required is identical.
This series covers Robert Carver's Systematic Trading (Harriman House, 2015). Part 1 covers the case for systematic thinking. Part 2 covers the technical toolkit. Part 3 covers the full quantitative framework. Nothing in this series constitutes investment advice.
Leave a comment ✎