Parametric Value at Risk and expected shortfall
One command in the Portfolio pack, available in the CLI, as an MCP tool and as a JavaScript import: portfolio var.
What it needs, and why
Every input is checked before anything is calculated. value and vol are required; the rest refine the answer.
| Input | Required | The question it asks | Why it matters |
|---|---|---|---|
value | yes | What is the total portfolio value? | Risk is reported in dollars against it. |
vol | yes | What annualized volatility should the estimate use? | The library has no volatility of its own; the figure comes from you. |
Requests it answers
- “how much could this portfolio lose”
- “what is the value at risk”
- “downside risk in a bad day”
An agent with this pack loaded picks the command from phrasing like that, asks for whatever input is missing, and reports the figures with the method that produced them.
Run it
node bin/wealth-skills.js portfolio var --value 1000000 --vol 0.14 --confidence 0.99Limits it inherits from wealth-portfolio
- Tax-loss harvesting checks only purchases in the 30 days *before* the sale, across the lots supplied. Confirm separately that nothing substantially identical is bought in the 30 days after, including in IRA and spouse accounts. Replacement candidates track a different index, but whether a fund is "substantially identical" is a judgment for the advisor or tax professional. No replacement is suggested for total-bond funds.
- Backtests use approximate embedded annual returns and capture drawdowns at year-end only.
- Forward-simulation regime assumptions are illustrative, not forecasts; pass your firm's capital market assumptions for client work.
- VaR is parametric normal and only as good as the volatility you supply.
The full pack, its other 10 commands and what it deliberately leaves alone are on the Portfolio page.