Portfolio Heat Management: How Much Total Risk Should You Have Open at Once?

Most traders know the 1% rule. Very few realize that eight "safe" 1% positions can still wreck an account in a single session.

That's because position sizing only answers half the question. The other half — the one that decides whether you survive a bad week — is how much risk you have open in total, across every position at once. Traders call this portfolio heat, and managing it is one of the sharpest dividing lines between consistent traders and blown accounts.

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The Problem: Your Risk Adds Up Faster Than You Think

Here's a scenario that plays out somewhere every single week:

You risk 1% per trade — textbook stuff. Monday you go long EUR/USD. Tuesday, long GBP/USD. Wednesday, long AUD/USD. Thursday you add two US index positions and a tech stock. By Friday you're running six open positions.

Each trade is "only" 1% risk. But look closer:

• EUR/USD, GBP/USD, and AUD/USD are all effectively short-dollar trades. One dollar rally hits all three.
• Your index longs and tech stock move together the moment risk sentiment turns.
• You don't really have six independent 1% bets. You have two clustered bets worth roughly 5% of your account, dressed up as six.

Then the dollar rips higher Friday morning after a hot inflation print. Three stops fire at once. The indices gap against you. Five to six percent is gone in hours — on a "conservative" 1% plan.

Per-trade risk limits protect you from any single trade. Portfolio heat limits protect you from all your trades at once.

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What Portfolio Heat Actually Is

Portfolio heat (also called total open risk or aggregate risk exposure) is the sum of the risk on every open position, expressed as a percentage of your account.

Portfolio Heat = (sum of risk per open position) / account balance x 100

Risk $100 on each of four open positions in a $10,000 account? Your heat is 4%.

The key word is risk, not size. A $50,000 position with a tight stop might only risk $100. A $5,000 position with a loose stop might risk $400. Heat measures your distance to the exits, not your notional exposure — which is exactly why traders who only look at position size chronically underestimate their true exposure.

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The Four-Layer Heat Framework

Professional desks manage heat in layers. You can copy the structure with four numbers:

1. Per-trade risk: 0.5-1%

Your baseline. This is standard position sizing — and it's only the input. The layers below are where most retail traders stop, and where the real protection begins.

2. Total heat cap: 3-6%

A hard ceiling on the sum of all open risk. Conservative traders and larger accounts sit toward the lower end. If you're swing trading part-time, anything above 6% total heat means a normal losing streak quickly becomes a serious drawdown.

3. Correlated cluster cap: 2-3%

Positions that would probably lose together share one limit:

• Currency pairs sharing a currency (EUR/USD, GBP/USD, and AUD/USD all lean on the dollar)
• Stocks in the same sector, or heavyweights in the same index
• Anything driven by the same macro factor — oil, interest rates, risk-on sentiment

Three "different" energy stocks plus a crude oil long? That's one trade wearing four costumes.

4. Single-event exposure: 1-2%

Before scheduled catalysts — CPI, FOMC, earnings — total heat exposed to that event should stay minimal. One headline can gap straight through multiple stops at the same time.

Rule of thumb: if two positions would likely stop out on the same headline, they are one position for heat purposes.

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How to Check Your Heat in 60 Seconds

1. For each open position, note your stop distance and what you lose if stopped.
2. Convert each to a percentage of your current account balance.
3. Sum everything. That number is your heat.
4. Group positions into correlation clusters and sum those too.
5. Before any new entry, ask: does this push me over a cap? If yes, the trade waits — or the weakest open position gets closed first.

Run the Friday scenario through it: three FX positions at 1% each, two index positions at 1% each, one tech stock at 1%. Total heat: 6%. Dollar cluster: 3%. Risk-sentiment cluster: 3%. On paper, six diversified trades. In reality, two maxed-out cluster bets — before a single new setup has even been considered.

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What to Do When You're at the Cap

Hitting your heat limit isn't the problem. Ignoring it is. Your options, in order of preference:

• Skip the trade. The market will offer another setup. Your account won't offer another drawdown budget.
• Close the weakest position and take the new one. Forced ranking between your best and worst idea is one of the most underrated discipline tools in trading.
• Tighten stops on laggards. Reducing open risk makes room without adding new exposure.
• Do nothing and wait for winners to reach breakeven — heat falls automatically as stops move to entry.

What you never do is quietly raise the cap "just this once." Most blown accounts started with exactly that exception.

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Why This Belongs in Your Journal

Portfolio heat is only useful if you can see it, and the fastest way to see it is in your trade journal:

• Log your total open risk with every new entry. One number. Ten seconds.
• Tag correlated clusters so your review shows the real structure of your exposure, not just a list of tickers.
• Compare heat levels to outcomes. Pull up your worst losing weeks and check the heat going into them. Most traders discover their deepest drawdowns happened at peak heat — proof the cap matters.

Once you see that pattern in your own data, the heat limit stops feeling like a restriction. It becomes the rule that saved you. This is exactly the kind of insight a tool like LogYourTrade is built for: log total open risk per trade, and your reviews surface the connection between overexposure and drawdown automatically.

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The Bottom Line

Position sizing keeps single trades survivable. Portfolio heat keeps your account survivable.

Set the four caps — per trade, total, per cluster, per event — write them into your trading plan, and check them before every entry. The math takes a minute. The drawdowns it prevents take months to recover from.

If you're not tracking total open risk yet, start today: open your journal, list your current positions, and add up the damage. That number is your starting line.