Portfolio Management Tools
Risk-Budget Allocation Tool
Investment Education, Research & Tools for Smarter Decisions.
Enter hypothetical positions or asset classes with weights and volatilities. See how each allocation consumes your total portfolio risk budget and what happens when you shift the weights.
Direct Answer
A risk-budget allocation tool shows how much of a portfolio's total risk each position or asset class consumes, based on its weight and volatility, rather than looking at capital weights alone. Enter hypothetical positions with weights and volatilities to see each holding's share of the risk budget and how that share shifts when weights change. This reveals concentration that capital weights alone can hide, for educational use only.
Risk-Budget Allocation Tool
Enter hypothetical positions with weights and volatilities. The tool calculates each position's marginal risk contribution and shows how much of the total risk budget each consumes. Assumes zero correlation between positions (see methodology below).
Results
Risk contribution by position
| Position | Weight | Volatility | Risk contrib. | Risk share | Budget target | Status |
|---|
Methodology
Risk budgeting assigns a share of a portfolio's total risk capacity to each position or asset class before sizing positions. This tool uses the marginal risk contribution (MRC) approach under a simplified zero-correlation assumption, which is appropriate for educational exploration of how weights and volatilities interact.
Risk contribution per position
For each position i, the marginal risk contribution is:
RCi = wi × σi
Where wi is the weight of position i and σi is its annualized volatility. Under zero correlation, each position contributes to total portfolio risk independently of the others.
Portfolio volatility (zero-correlation)
Under the assumption that all pairwise correlations are zero, portfolio variance is the sum of weighted variances:
σp = √(∑ (wi × σi)2)
This is a lower bound on actual portfolio volatility. When assets are positively correlated, real portfolio volatility will be higher.
Risk share
Each position's share of the total risk budget is:
RiskSharei = RCi / ∑ RCj × 100%
A position consumes more of the risk budget either by having a higher weight, a higher volatility, or both. Equal risk budgeting, sometimes called risk parity, targets equal risk shares across all positions rather than equal capital weights.
Risk budget target
The tool compares each position's actual risk share against an equal-budget target of 100% / N where N is the number of positions. A position that exceeds its equal budget target is flagged as over-budget; one below it is under-budget. You can also set custom budget targets per position using the input column.
Dollar risk amount
The estimated one-year 1-sigma dollar loss for each position is:
DollarRiski = PortfolioValue × wi × σi
This is a point estimate under normality, not a worst-case figure. Actual losses in tail scenarios can be significantly larger.
Limitations
- Zero correlation: The tool assumes all assets are uncorrelated. In reality, equities tend to be positively correlated during market stress, which means true portfolio volatility will exceed the estimate shown here.
- Constant volatility: Volatility is assumed constant. In practice it is time-varying and can spike sharply in stress periods.
- Normality: The dollar risk figures assume returns are normally distributed. Fat-tailed return distributions mean actual losses exceed these figures more often than a normal distribution predicts.
- Hypothetical only: No real portfolio data is used. Results reflect only the numbers entered and do not represent any actual portfolio or investment position.
Frequently Asked Questions
What is a risk budget and why does it matter?
A risk budget defines how much total portfolio risk, typically measured as annualized volatility, a portfolio is permitted to carry, and then allocates that risk capacity across positions or asset classes. Rather than sizing positions by dollar weight alone, risk budgeting asks: how much of the portfolio's total risk does each position contribute?
This matters because two positions with the same dollar weight can contribute very different amounts of risk if their volatilities differ. A 10% position in a stock with 40% annualized volatility contributes four times more marginal risk than a 10% position in a bond fund with 10% volatility. Risk budgeting makes this visible and lets you design position sizing around a risk target rather than a capital target.
What does the zero-correlation assumption mean for my results?
This tool assumes all pairwise correlations between positions are zero. Under zero correlation, each position's risk contribution is independent of the others, and portfolio variance is simply the sum of each position's squared weighted volatility. This makes the math transparent and the relationship between weight, volatility, and risk share easy to observe.
In reality, most asset classes are positively correlated to some degree, especially equities during market downturns. Positive correlation means the true portfolio volatility is higher than the tool estimates. Use the results as a directional guide for understanding how weight and volatility interact, not as a precise portfolio volatility forecast.
What is risk parity, and how does it relate to equal risk budgeting?
Risk parity is a portfolio construction approach where every position is sized so that it contributes an equal share of the portfolio's total risk. If you have four positions and target equal risk budgeting, each position should consume 25% of the portfolio's total risk, regardless of its dollar weight. Achieving equal risk shares typically means holding more of lower-volatility assets and less of higher-volatility assets compared to an equal-weight portfolio.
The "Risk-parity-style" preset in this tool shows an example where weights are adjusted inversely to volatility so that each position's risk contribution is roughly equal. You can use the tool to experiment with different weight combinations and observe how close you can get to equal risk shares in a hypothetical portfolio.
How do I interpret a position that is flagged as "over budget"?
An over-budget flag means a position is consuming more than its equal share of the portfolio's total risk budget. For example, if you have four positions and the equal budget target is 25% each, a position flagged as over-budget is taking more than 25% of total risk. This does not mean the position is wrong. It means you are making an active bet by tilting risk toward that position. An active tilt is only a problem if it is unintentional or if it creates more concentration than you intended.
To bring an over-budget position within its target, you can reduce its weight, choose a different asset with lower volatility, or increase the weight and volatility of other positions to dilute the over-budget position's share.
Can I use this tool with real portfolio positions?
This is a hypothetical educational tool. You can enter any names, weights, and volatility estimates you like, the tool does not connect to any brokerage, exchange, or data provider. No account details, API keys, or personal financial data should be entered here. The results are illustrative calculations based only on the numbers you type in.
If you want to apply risk budgeting to a real portfolio, consult a qualified financial professional who can account for real correlation structures, tax implications, transaction costs, and your specific financial situation.
Where do volatility estimates come from, and how should I choose them?
Volatility estimates are not provided by this tool, you supply them based on your own research. Common sources include historical realized volatility (the annualized standard deviation of daily or weekly returns over a look-back window), implied volatility from options markets, or volatility estimates from academic or industry research on asset class risk premia.
A common approach for equities is to calculate the annualized standard deviation of daily returns over the past 252 trading days. For multi-asset portfolios, researchers often use longer windows (3-5 years of monthly returns) to reduce noise. Remember that historical volatility is backward-looking and past volatility does not guarantee future volatility, asset risk regimes can shift substantially over time.
Why measure risk with volatility rather than with a stop-loss distance?
Volatility aggregates. Position contributions computed from volatility and weight sum to portfolio volatility, which is what makes a budget add up to a whole. Stop distances do not combine that way, because they describe one specific path per position and give no basis for combining several positions that could move together. Stop-based figures are useful for sizing a single trade; a portfolio-level budget needs a measure with an additive structure.
Does a position's risk share equal its capital share if every holding has the same volatility?
Under the tool's assumption of no correlation, yes. When volatilities are identical, each position's contribution reduces to its weight, so the risk table and the capital table match exactly. Any divergence between them therefore comes entirely from volatility differences. That equivalence is a useful check: if the two tables look the same and the volatilities entered are not the same, an input has not been applied the way it was intended.
How should the output be read when the portfolio holds a large cash position?
Cash contributes essentially no volatility, so it takes almost no share of the risk budget while occupying a real share of capital. Every other position's reported risk share therefore rises relative to its capital weight. That is the correct reading rather than a distortion: it shows that the invested portion is carrying all of the portfolio's risk, which is precisely the effect a large cash allocation has.