EducationRisk~18 min readUpdated 30 September 2026
The short answer
Portfolio heat is the sum of your open risk across every position. Three trades at 1% each is not 3% risk if the positions are correlated. It can be 5%, 7%, or more. Two rules cap this: no more than 3% total heat at any time, and no more than one position per correlation group. Get this wrong and every risk rule you learned in Lesson 44 gets silently broken.
Why this follows stop placement
Lesson 46 gave you structural stops. This lesson answers what happens when those stops are all on correlated instruments. A 20-pip stop on EUR/USD, a 20-pip stop on GBP/USD, and a 20-pip stop on AUD/USD are not three independent bets. They are three versions of the same short-dollar trade. If the dollar rallies, all three stop out in the same minute.
The 1% rule limits per-trade risk. Portfolio heat limits total risk. Correlation determines what total risk actually is.
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Written by the Trade To The Top team|Reviewed 30 September 2026
Portfolio heat methodology cross-checked against Trade Your Way to Financial Freedom (Van Tharp), the correlation-adjusted risk frameworks in Advances in Financial Machine Learning (López de Prado), and the portfolio-heat limits published in professional CTA risk documentation. Correlation coefficients verified against the standard 90-day rolling correlations on G10 FX majors.
You risk 1% per trade. You have three trades open. Your account is up. Everything feels fine. Then a dollar rally stops all three trades out in the same five minutes. You lose 3% in an afternoon. You thought you had three independent trades. You actually had one trade at 3x the intended size. This lesson is about the difference.
Key takeaways
Portfolio heat is total open risk. Three 1% trades is nominally 3% heat. It is effectively more if they are correlated.
Correlation determines the multiplier. Two instruments at 0.85 correlation behave like one position at 1.5x the size.
Cap total heat at 3%. Three trades at 1% each, and no more.
One position per correlation group. EUR/USD and GBP/USD are the same group. AUD/USD and NZD/USD are the same group.
Currency exposure is the underlying risk. Long EUR/USD + long GBP/USD + short USD/CHF = short USD three times.
Correlation changes with the regime. Two pairs at 0.40 in Q1 can be 0.85 in Q3. Re-check quarterly.
Inverse correlation is still correlation. Long EUR/USD and long USD/CHF is one trade, not two.
Correlated positions should be sized as one. If you must take both, split the risk between them.
Watch the news calendar. Correlation spikes during high-impact events. Two positions that behaved independently all week move together on NFP.
Total heat is the only number that matters at the portfolio level. Track it like you track your equity.
Portfolio heat is the sum of the risk on all your open positions, expressed as a percentage of your account. If you have three trades open, each risking 1%, your portfolio heat is nominally 3%.
It answers a question that per-trade risk cannot: if everything went wrong at once, how much would I lose?
The answer is usually larger than the trader thinks, because the answer depends on correlation. If your three positions are correlated, they will hit their stops at the same time. Three positions that stop out together are not three losses of 1%. They are one loss of 3%.
PORTFOLIO HEAT · THE SUM OF OPEN RISK
Conceptual diagram · three open positions and how their risk sums up
Three positions at 1% each. Portfolio heat is nominally 3% — but is it really 3%?
Common mistake
Tracking per-trade risk and ignoring total heat. A trader who never has more than 1% at risk per trade can still lose 6% in a day if they hold five correlated positions. The 1% rule applies to the trade. Portfolio heat applies to the portfolio. You need both.
Nominal vs effective risk
Here is where the math gets uncomfortable. Nominal risk is the arithmetic sum of your open risk. Effective risk is what you would actually lose if the market moved against all positions at once — which is exactly what happens when positions are correlated.
Scenario
Nominal risk
Effective risk
3 uncorrelated trades at 1%
3%
~3% — losses arrive at different times
2 correlated + 1 uncorrelated
3%
~4.5% — the two correlated trades move as one
3 correlated trades at 1%
3%
~5–7% — same trade three times
3 inversely-correlated trades
3%
~5% — one directional bet in three formats
NOMINAL VS EFFECTIVE · THE SAME 3% THAT IS NOT 3%
Two scenarios · same nominal risk, wildly different effective risk
Same nominal 3%. Effective risk is 3% on the left and 5–7% on the right.
Three positions that stop out together are one position at three times the size.
The correlation matrix
Correlation is measured on a scale from −1 to +1. +1 means the two instruments move together. −1 means they move opposite. 0 means no relationship. In practice, most FX pairs sit somewhere between −0.9 and +0.9, with clusters at the extremes.
CORRELATION MATRIX · G10 FX MAJORS
90-day rolling correlation · highlighted cells are correlation groups above 0.70
EUR/USD, GBP/USD, and AUD/USD form the "short dollar" group. Only one belongs on the open list.
Currency exposure
Correlation pairs are a surface-level view. The deeper view is currency exposure — which currencies you are actually long and short, across all positions combined.
Every FX pair has two currencies. When you hold multiple pairs, you may be accumulating the same directional bet on a single currency without realising it.
Currency exposure — worked example
01
Position 1: Long EUR/USD. Exposure: long EUR, short USD.
02
Position 2: Long GBP/USD. Exposure: long GBP, short USD.
03
Position 3: Short USD/CHF. Exposure: short USD, long CHF.
04
Net exposure: long EUR, long GBP, long CHF, short USD three times.
05
Conclusion: three "different" trades, but the real position is one large short-dollar bet. Effective risk: 3–4%.
CURRENCY EXPOSURE MAP · THE REAL BET BEHIND THE POSITIONS
Three positions collapsed into net currency exposure
Three different pairs. One short-dollar position — at three times the intended risk.
The 3% cap
Given all of this, the rule that keeps a multi-position trader alive is simple. Total portfolio heat must never exceed 3%. Not 6%. Not 10%. Three percent.
The 3% portfolio heat cap
01
Per-trade risk: 1% of account balance. Never more.
02
Maximum open positions: three at any time.
03
Maximum portfolio heat: 3%. If three positions are open, no new ones until one closes.
04
One per correlation group: EUR/USD and GBP/USD do not both stay open. USD/JPY and USD/CHF do not both stay open.
05
Correlation-adjusted sizing: if two correlated positions must be open, split the risk. 0.5% each, not 1% each.
06
News blackout: if a tier-one release is imminent, close the correlated positions or reduce to one.
Worked example — same three positions, two correlation-aware traders
Account
$10,000
Positions
Long EUR/USD, Long GBP/USD, Long AUD/USD
Direction
All long dollar-short
Correlation
0.75 to 0.85
Event
DXY rally on stronger-than-expected US data
Trader A — Ignores correlation.
Sizes each position at 1% = $100 risk each.
Nominal risk: 3% = $300.
DXY rallies. All three stops hit within 15 minutes.
Actual loss: 3 × $100 = $300. Account at $9,700.
Drawdown: 3% in one event.
Trader B — Correlation aware.
Sees all three positions are in the same group.
Takes ONE position (the strongest setup) at 1%.
Sizes the other two at 0% (skipped).
DXY rallies. One stop hit. Others never taken.
Actual loss: $100. Account at $9,900.
Drawdown: 1%. Same market move, one-third the damage.
SAME MARKET. SAME ANALYSIS. DIFFERENT RESULT.
Trader A took "three trades." Trader B took one. The market did the same thing to both. Trader B lost one-third as much. That is the whole lesson in one comparison.
How to manage multiple positions
When you have more than one position open, three additional rules apply.
Managing multiple positions
01
Track total heat daily. Write down the sum of open risk every morning. If it exceeds 3%, close the weakest position.
02
Close the weakest first. When reducing, ask which position has the worst setup quality, not the worst P&L.
03
Check correlation groups before every new entry. Before opening, ask which existing positions overlap. If one overlaps, do not take the new trade.
04
Reduce size in correlated entries. If you must take a correlated position, halve the risk. 0.5% instead of 1%.
05
Reduce heat before news. Before NFP, FOMC, or CPI, either close correlated positions or halve the size.
06
Never add to a losing portfolio. If open heat is under water and you want to trade more, close first. Adding to a losing book is how a 3% day becomes a 6% day.
The seven portfolio rules
The rules — print these
01
Cap total heat at 3%. Sum of open risk. Not 4%. Not 5%. Three.
02
Maximum three positions. Three trades at 1% each fills the cap. More trades means smaller size.
03
One position per correlation group. EUR/USD, GBP/USD, AUD/USD, NZD/USD are one group.
04
Check currency exposure, not just pair correlation. Three pairs can collapse into one directional bet.
05
Halve correlated size. If you must hold two correlated positions, size each at 0.5%.
06
Reduce heat before tier-one news. Close the weakest correlated position or halve everything.
07
Re-check correlations quarterly. Two pairs at 0.40 can become 0.80 in a market regime shift.
When this fails
When this fails
Correlations shift during crises. Pairs that were uncorrelated in normal markets converge during risk-off events. In March 2020, correlations across all risk assets spiked above 0.90. Assume correlations go up in a crisis, not down.
Currency exposure is hidden. A long EUR/USD and a long USD/CHF is a short-dollar position in disguise. If you only check the pair names, you miss it. Always decompose into underlying currencies.
Portfolio heat is tracked on entry only. A trade that starts at 1% risk can become 3% risk if you move the stop wider. Never move the stop wider. If you do, recalculate heat immediately.
Grid positions are ignored. If you are running a grid (Lesson 40), portfolio heat is not capped at 1% per grid level. Five grid levels at 0.5% each is 2.5% heat on a single trade. Count grid risk as portfolio heat.
Correlation-based sizing is too aggressive. If you have three correlated positions, sizing each at 1% gives effective risk of 5–7%. Sizing each at 0.33% gives effective risk near 1.7%. Do that.
You cap heat but not direction. All long positions in correlated markets is a directional bet even if the heat cap is respected. Direction caps are separate from heat caps. If the whole book is one direction, treat the whole book as one position.
If you remember nothing else: three positions at 1% each is not 3% risk. It is 3% heat plus whatever multiplier the correlation gives you.
In one box
Portfolio heat is the sum of open risk.
Cap it at 3%. Three positions at 1% each.
One per correlation group. EUR/USD, GBP/USD, AUD/USD — same group.
Reduce heat before news. Tier-one releases spike correlation.
Correlations rise in a crisis. Assume 0.40 becomes 0.85 when it matters.
Re-check correlations quarterly. Regimes change.
See it in practice. Our free trading journal tracks portfolio heat alongside every trade. Log your open positions daily. See the correlation overlap before your stops are hit, not after.
5 questions · immediate feedback · retake any time
Question 01 of 05
What is portfolio heat?
Correct: B. Portfolio heat is the sum of open risk. Three positions at 1% each is 3% nominal heat. Correlation determines what the effective heat actually is.
Question 02 of 05
You have three long positions: EUR/USD, GBP/USD, and AUD/USD. Each risks 1%. What is your effective risk?
Correct: C. EUR/USD, GBP/USD, and AUD/USD are all long dollar-short. They move together. Three positions at 1% each with 0.75+ correlation gives effective risk of 5–7%.
Question 03 of 05
What is your maximum total portfolio heat?
Correct: A. Cap portfolio heat at 3%. Three positions at 1% each. Any more and the effective risk during correlation spikes is too high.
Question 04 of 05
You want to trade long USD/CHF while already holding long EUR/USD. What is your actual currency exposure?
Correct: D. Long EUR/USD = long EUR, short USD. Long USD/CHF = long USD, short CHF. The two USD exposures are opposite. Net: long EUR, long CHF, and the USD exposure cancels. Wait — actually re-check: long EUR/USD is short USD; long USD/CHF is long USD. The two USD exposures cancel, but you still have two separate directional bets on EUR and CHF. The point: decomposing exposure reveals hidden structure that pair names hide.
Question 05 of 05
Before a tier-one news release, what should you do with correlated positions?
Correct: C. Correlation spikes during tier-one news events. Pairs that moved independently all week can move together on NFP. Reduce heat before the release: close the weakest correlated position or halve size on all of them.