Direct Answer
A portfolio shock matrix applies multiple stress scenarios at once to up to five positions, using each position's value, equity beta, duration, and credit-spread sensitivity to estimate profit-and-loss under each scenario. The matrix view shows which positions drive the largest stress losses and which scenarios pose the greatest portfolio-wide risk. Results are educational estimates only, not a guarantee of actual stress performance.
Tool
Portfolio Positions (up to 5)
Enter positions above and click Run Shock Matrix to see estimated stress P&L across four scenarios.
Uses user-entered data only. No data is stored or transmitted. Estimates are based on simplified linear factor models and do not account for correlation between factors or nonlinear instrument payoffs.
How to Use This Tool
Enter each portfolio position's name, current market value in dollars, equity beta (sensitivity to broad equity market moves), modified duration in years (for rate sensitivity), and credit spread duration in years (for credit spread sensitivity). Leave equity beta at 0 for pure bond positions with no equity sensitivity; leave duration and spread duration at 0 for pure equity positions.
The tool applies four pre-calibrated stress scenarios simultaneously: (1) a 2008-type credit crisis (equity −38%, Treasury yield −80 bps, IG spreads +280 bps, HY spreads +900 bps); (2) a COVID-2020 acute shock (equity −34%, Treasury yield −60 bps, IG spreads +120 bps); (3) a 2022-type rate shock (equity −22%, Treasury yield +250 bps, IG spreads +70 bps); and (4) a stagflation scenario (equity −28%, Treasury yield +180 bps, IG spreads +120 bps, HY spreads +350 bps). For each position, the stress P&L is calculated as: Equity P&L = Value × Beta × Equity Shock; Rate P&L = Value × Duration × Rate Shock; Spread P&L = Value × Spread Duration × Spread Shock. Total position P&L is the sum of these components.
The matrix output shows P&L for each position under each scenario, plus row totals (position total across all scenarios) and column totals (portfolio total for each scenario). Positions with large negative values across multiple scenarios are the primary stress risk drivers. The scenario column with the most negative total is the scenario that most threatens the portfolio given its current composition.
Understanding the Outputs
The portfolio total row at the bottom of the matrix shows the estimated total loss or gain under each scenario as a dollar amount and as a percentage of total portfolio value. Green values indicate positions or scenarios where the portfolio gains (e.g., bonds gaining in a flight-to-safety equity scenario), and red values indicate losses. The dominant loss scenario, the scenario with the most negative portfolio total, is the primary stress risk given current portfolio composition.
Position P&L attribution across the rows reveals which positions drive the stress loss. A position with a small portfolio weight but a large beta (high-beta small-cap stock) can contribute disproportionately to equity stress P&L. A long-duration bond position may show a large gain in an equity crisis scenario (if rates fall as a flight-to-safety) but a large loss in a rate-shock scenario. The matrix makes these cross-scenario trade-offs visible in a single view.
For portfolios with material credit exposure (high-yield bonds, floating-rate bank loans, corporate bonds), the 2008 credit-crisis scenario typically shows the most severe losses because it applies the largest credit spread shock. For portfolios heavily invested in long-duration bonds alongside equities, the 2022 rate shock typically shows both equity and bond losses simultaneously, the scenario that eliminates the typical cross-asset diversification benefit. The comparative view across all four scenarios in the matrix is more informative than any single scenario alone.
The tool uses simplified linear factor models. For positions with nonlinear characteristics (options, callable bonds, structured products), the estimates will not be accurate, use full revaluation methods as described in the options stress testing guide. The tool is appropriate for straightforward portfolios of equity ETFs, bond ETFs, and plain vanilla individual bonds or stocks.
Assumptions and Limitations
- Linear factor model: assumes P&L is proportional to factor exposure × factor shock, with no nonlinearity. Not appropriate for options or structured products.
- Factor independence: each factor's P&L contribution is computed independently and summed. Cross-factor correlations are not modeled explicitly, the scenarios implicitly combine factor shocks, but the interaction effects between factors within a position are not captured.
- Instantaneous shock: the scenarios are applied as instantaneous shocks to current positions. Time decay, interim rebalancing, and path-dependent effects are not modeled.
- Factor shocks are pre-calibrated: the four built-in scenarios use fixed factor shock magnitudes based on historical data approximations. Your specific portfolio's most relevant stress scenario may differ.
- No liquidity adjustment: the tool computes mark-to-market stress P&L only. Additional liquidation costs for illiquid positions are not included. See the liquidity stress guide for adjustment methodology.
Frequently Asked Questions
How do I find the equity beta for a stock or ETF?
Beta is published by most broker platforms and financial data sites (Yahoo Finance, Morningstar, Bloomberg) for individual stocks and ETFs. On Yahoo Finance, beta is listed in the "Statistics" section for any ticker. For index ETFs (SPY, QQQ, IWM), the beta to the relevant index is approximately 1.0 by design. For actively managed funds, check the fund's fact sheet or risk disclosure. If no published beta is available, estimate it by regressing the position's monthly returns on the S&P 500's monthly returns over the past 36 months using a spreadsheet.
What is modified duration and where do I find it?
Modified duration measures a bond position's sensitivity to interest rate changes, the percentage price change per 1% change in yield. For bond ETFs, modified duration (also called "duration to worst") is published in the ETF's fund fact sheet and on the fund provider's website (e.g., iShares, Vanguard, PIMCO). For individual bonds, duration is available from your broker's bond information page or from FINRA's Bond Center. For a rough estimate: zero-coupon bonds have duration equal to maturity; coupon-paying bonds have duration shorter than maturity. The 10-year Treasury note typically has duration of approximately 8-9 years.
What is credit spread duration and how is it different from interest rate duration?
Credit spread duration measures a bond position's sensitivity to changes in the credit spread over Treasuries, the additional yield investors require for taking credit risk. For plain-vanilla fixed-rate corporate bonds, spread duration is approximately equal to modified duration. For callable bonds or floating-rate bonds, spread duration differs from rate duration. In this tool, you can enter the same value for both duration and credit spread duration for most plain-vanilla corporate bonds, then review the results. The credit spread shock in each scenario is applied to the spread duration; the rate shock is applied to the (rate) duration. Positions with high spread duration lose significantly in credit-crisis scenarios even if their interest rate duration is low.
Why might my portfolio show a gain in some scenarios?
Treasury bonds, gold, and certain defensive assets typically gain in credit-crisis and equity-crash scenarios through flight-to-safety demand. If your portfolio has meaningful bond allocation, the bond position may show gains from falling Treasury yields in the 2008 and COVID scenarios, partially offsetting equity losses. Similarly, gold positions often gain during acute stress events. The matrix will show these offsets as green (positive) cells, and the scenario total will reflect both the losses from risky assets and the gains from safe-haven assets. In the 2022 rate-shock scenario, however, bonds also lose (rates rise, bond prices fall), so the typical offset disappears.
Can I use this tool for a portfolio with options?
No, the linear factor model used in this tool is not appropriate for options or other nonlinear instruments. Options P&L is a curved function of the underlying price, and the linear beta approximation significantly underestimates or overestimates option P&L for the large moves typical of stress scenarios. For options, use full revaluation as described in the options stress testing guide. You can still use this tool for the non-option positions in your portfolio and add the option P&L estimate separately from a full revaluation calculation.
What does the matrix view show that running one scenario at a time does not?
It shows which position drives the loss in each scenario, and whether the same one drives all of them. A portfolio where one holding dominates every column has a concentration problem rather than a scenario problem, and no change to the scenario set will reveal that as clearly as the side-by-side view. The matrix also exposes positions that help in one scenario and hurt in another, which a single run reports as a net number.
How should a cash position be entered?
With its value and sensitivities set to zero for equity beta, duration and credit spread, so it contributes no profit or loss in any scenario while still counting toward total portfolio value. That matters because the results expressed as a share of the portfolio depend on the denominator. Omitting cash entirely makes every loss look larger as a percentage than it is, which is the more common error than entering it incorrectly.
How should a portfolio with more than five holdings be entered?
By grouping holdings into sleeves that share risk characteristics and entering each sleeve as one line, with its value summed and its sensitivities set to the value-weighted average of the members. That keeps the aggregate result accurate while losing the per-position attribution inside each sleeve. Any holding large enough to matter on its own is worth keeping as a separate line, since averaging it into a sleeve is exactly what hides a concentration.
Do the results include the cost of actually liquidating positions?
No. The figures are mark-to-market estimates of what the positions would be worth under each scenario, which assumes prices can be observed rather than that the holdings could be sold at them. Bid-ask spreads widen under stress, large positions move the price against the seller, and some markets stop quoting. Those effects are treated separately because they depend on position size relative to normal trading volume, which the sensitivities alone do not capture.
References
- Federal Reserve Bank of St. Louis. FRED Economic Data. Historical Treasury yields and credit spreads used to calibrate built-in scenarios. https://fred.stlouisfed.org
- S&P Dow Jones Indices. S&P 500 historical return data. https://www.spglobal.com/spdji/en/indices/equity/sp-500/
- Jorion, Philippe. Value at Risk: The New Benchmark for Managing Financial Risk. 3rd ed. McGraw-Hill, 2006. Chapter 14 covers factor-based stress test methodology.
Disclaimer
This tool is for educational and informational purposes only. Results are estimates based on simplified linear factor models and pre-calibrated historical scenarios. They do not constitute investment advice or a guarantee of future portfolio performance. All calculations use user-entered data only, no data is stored or transmitted. Consult a qualified financial professional before making investment decisions.