Portfolio Heat: How to Audit Total Open Risk Across Correlated Trades

Three trades can each meet your position-sizing rule and still leave too much of your account exposed to the same market move. A technology stock, a semiconductor stock, and a growth-heavy fund may have different entry signals while depending on much of the same buying pressure.

Portfolio heat makes the combined exposure visible. Start by adding the amount each open position could give back before its active stop. Then check how much of that total sits in trades that could move against you together.

The audit works best when you state exactly what you are measuring. Risk from entry and risk from today’s equity answer different questions.

Define the portfolio heat you are measuring

For this guide, portfolio heat is the sum of current-price-to-active-stop exposure, divided by current account equity. It estimates the decline from today’s marked account value if every included position exited at its listed stop price, before costs.

Portfolio heat % = total current-to-stop exposure ÷ current account equity × 100

This is a stop-based scenario. It does not estimate the probability of that outcome, and actual losses can exceed it.

Keep initial planned risk in a separate column: the exposure accepted between the entry price and the original stop when the trade opened. That historical measure helps you review sizing and results. Current-to-stop exposure helps you audit what the open book could give back now.

Suppose you bought 100 shares at $100 with a stop at $98. The original planned risk was $200. If the shares now trade at $105 and the stop remains at $98, current-to-stop exposure is $700. It includes $500 of unrealized profit plus $200 below entry.

Moving the stop to $102 would leave $300 of current-to-stop exposure. A fill at that stop would preserve a $200 profit before costs, but the account would still fall $300 from its current value.

Build one reliable position list

Take an account snapshot and record:

Instrument and account
Long or short direction
Remaining position size
Entry price and current price
Active stop price, order type, and order status
Contract multiplier, where relevant
Currency in which the position’s P&L is calculated
Conversion rate into your account’s reporting currency
Shared exposure, such as sector, currency, or market driver

Store the original quantity and original stop separately if you want to preserve the initial plan. After partial exits, the remaining quantity belongs in the current audit.

Use current equity, including open P&L, for the same accounts and time as the position snapshot. Mixing positions from two accounts with the equity of only one distorts the percentage. Cash balance and available buying power are different measures.

Check the broker’s live position and order records. A stop written in a journal does not establish that a protective order is working.

Calculate each position’s stop exposure

For a simple linear position, the calculation is:

Stop exposure = remaining units × multiplier × adverse price distance × FX conversion rate

The adverse distance is current price minus stop for a long, or stop minus current price for a short. Use an FX rate expressed as reporting-currency units per one unit of the P&L currency. For ordinary shares, the multiplier is usually 1; when the currencies match, the FX factor is 1.

For example, a short position of 80 shares, currently at $50 with an active stop at $55, has $400 of current-to-stop exposure before costs: 80 × ($55 − $50).

Verify the product’s specifications before applying a multiplier. CME’s calculation guide explains how contract size and tick value determine futures P&L. The arithmetic here does not model margin calls, liquidation, or every derivative. Options, inverse contracts, and multi-leg strategies require product-specific analysis. For example, option value depends on inputs beyond the underlying price, including volatility and time to expiration.

A missing stop means this stop-based exposure is undefined. Flag it instead of entering zero; a total that excludes it is incomplete. If price has already reached or crossed the stop, investigate the order and fill status before trusting the calculation. A negative distance is a data or execution warning.

Work through a $50,000 account

The following positions are hypothetical. No partial exits or additions have occurred, so the original quantities are unchanged. All prices and P&L are in USD, all multipliers are 1, and current account equity is $50,000.

Position	Direction	Shares	Entry	Current price	Active stop	Current-to-stop exposure
Technology stock A	Long	100	$100	$105	$98	$700
Semiconductor stock B	Long	50	$200	$204	$196	$400
Retail stock C	Short	80	$52	$50	$55	$400
Total						$1,500

Portfolio heat = $1,500 ÷ $50,000 × 100 = 3%

Under the exact-stop assumptions, equity would decline from $50,000 to $48,500. The 3% describes this snapshot; it is not a recommended limit.

If the original stops were the same as the active stops shown, initial planned risk was $200 + $200 + $240 = $640. The larger $1,500 current figure reflects the open gains that could also be surrendered. Neither number should be relabeled to make the account appear less exposed.

Technology stock A and semiconductor stock B contribute $1,100, or 2.2% of account equity, to a technology-related cluster. That is about 73% of the total stop exposure in this example.

This concentration deserves a separate check. A sector selloff could threaten both positions even though their charts have different entry patterns. FINRA’s concentration-risk guide highlights the overlap that can arise within industries and between individual stocks and funds.

Group positions by the event or market move that could hurt them:

A technology or semiconductor selloff
A stronger or weaker reporting currency
An interest-rate repricing
A common commodity move
An earnings announcement or other shared catalyst

These groups are review labels, not measured correlations. Don’t multiply the total by an invented “correlation adjustment” or assume different tickers diversify the risk.

A position can belong to several groups. Review those overlapping groups individually; adding their subtotals would count some positions twice. Count every position only once in the portfolio total.

Keep gross stop exposure visible even when a short appears to hedge a long. Any hedge benefit needs a separate scenario with explicit assumptions. The positions may react differently, and their stops may trigger at different times.

Add the risks the stop calculation misses

Stop prices are planning inputs, not guaranteed fills. A stock stop order becomes a market order after triggering, and a fast move can produce a substantially different execution price. A stop-limit order can remain unfilled. FINRA explains these execution trade-offs.

Review overnight gaps, thin liquidity, trading halts, spreads, commissions, financing, and upcoming events. Currency conversion adds another assumption: today’s conversion rate may differ when a position closes.

Keep an adverse-execution scenario alongside the base calculation when relevant. In the example, suppose stock A fills at $96 instead of its $98 stop. That adds $200 of giveback, raising the portfolio scenario from $1,500 to $1,700, or 3.4% of current equity, if the other positions exit at their stops.

The extra $200 is an illustrative assumption, not a forecast or a worst-case boundary. Use assumptions relevant to the instrument and holding period, and label them clearly.

Use the audit before adding another trade

Compare the result with limits written for your account and strategy. Set those limits using your capacity for loss, tested strategy behavior, holding period, execution conditions, and any external account rules. No single heat percentage is safe for everyone.

Before a new entry, calculate its proposed contribution to both portfolio heat and the relevant exposure groups. If it would exceed a limit, the plan may call for a smaller position, skipping the trade, or reducing existing exposure under established exit rules.

Don’t tighten a stop simply to make the spreadsheet pass. Stop placement still needs to fit the strategy’s invalidation logic. UltraTrader’s guide to exit rules and risk management covers how to document those decisions.

A repeatable portfolio heat checklist

Reconcile current equity, positions, and working stops.
Calculate current-to-stop exposure in one reporting currency.
Flag missing stops, crossed stops, and unsupported instruments.
Sum each position once and divide by current equity.
Review shared-exposure groups and event risks.
Compare both the base and adverse-execution scenarios with your written limits.
Record the decision, assumptions, and snapshot time.

Repeat after meaningful price moves, fills, partial exits, or stop changes, and before accepting new risk. Preserve the snapshots so a later review shows what you knew at the time.

Use the companion calculator to organize the arithmetic, then record the reasoning in your trading journal. The useful result is a clear answer to two questions: how much could this open book give back at its stops, and how much of that exposure depends on the same market move?

Educational content only. This article describes a risk-recordkeeping method, not personalized investment advice. Trading involves risk of loss, and stop orders do not guarantee a maximum loss.