← 1-Year PathQ4 · Risk & Mastery

Week 40 — Portfolio Theory & Risk Metrics

Modern Portfolio Theory and the metrics that measure how much you can lose.

Week 40 of 52 · ~7 hours · 13 slides · exam + project

Measuring Risk

Risk isn't a feeling — it's a number you can measure and manage.

What you will learn

  • Understand risk/return and diversification
  • Use the core risk metrics
  • Read the efficient frontier

The efficient frontier

Risk (volatility)Return Efficient Frontier best return per unit of risk inefficient (dominated)
The efficient frontier

Risk vs return

Risk →Expected return CashBondsStocksReal estateCryptoHigher return demands higher risk — the spectrum.
Risk vs return

Risk and return are twins

There is no return without risk — the question is how much risk per unit of return. Modern Portfolio Theory formalizes this: combine assets to maximize return for a given risk, or minimize risk for a given return. Diversification is the free lunch that lowers risk without lowering expected return.

The core metrics

Volatility (standard deviation) measures how much returns swing. Sharpe ratio = excess return ÷ volatility (return per unit of risk). Maximum drawdown = the worst peak-to-trough loss. Beta = sensitivity to the market. Value at Risk = the worst loss at a given confidence.

💡 Reading the Sharpe ratio

A Sharpe of 1.0 means you earn 1 unit of excess return per unit of volatility — decent. Below 0.5 is poor; above 1.5 is excellent (and rare). A high return with huge volatility can have a low Sharpe — and vice versa. Sharpe is how you compare apples to oranges.

The efficient frontier

The efficient frontier is the curve of optimal portfolios — the highest return for each level of risk. Portfolios below the curve are inefficient (you could get more return for the same risk). The frontier is why diversification, not concentration, is the rational default.

💡 Drawdown is what you feel

Volatility is abstract; drawdown is real. A portfolio that falls 50% needs a 100% gain to recover. This is why risk management focuses on limiting drawdown — not just optimizing return. The best portfolio is the one you can hold through the worst drawdown.

The practical takeaway

Diversify across uncorrelated assets, measure your Sharpe and drawdown, and size so the worst realistic drawdown is survivable. Risk metrics aren't academic — they're the difference between a portfolio you can hold and one you'll abandon at the bottom.

❓ Quick check

The Sharpe ratio measures:

A) Total return
B) Return per unit of risk
C) Drawdown
D) Beta
(Knowledge check — full exam is next)

Key takeaways

  • No return without risk; diversification is the free lunch
  • Key metrics: volatility, Sharpe, max drawdown, beta, VaR
  • The efficient frontier = optimal risk/return portfolios

📝 Weekly Exam — pass with 80% to unlock next week

10 questions. Review the Deep Dive and courses before attempting.

1. Modern Portfolio Theory is about:
Risk/return optimization.
2. The Sharpe ratio equals:
Return per unit of risk.
3. A Sharpe ratio of 1.0 is:
1 unit return per unit risk.
4. Maximum drawdown is:
Worst loss from peak.
5. Beta measures:
Market sensitivity.
6. The efficient frontier is:
Optimal portfolios.
7. Diversification lowers risk:
The free lunch.
8. A 50% drawdown requires a ___ gain to recover:
Double to break even.
9. The best portfolio is one you can:
Survivability matters most.
10. Risk management should focus on:
Survivable drawdown.
Your score: —

🛠 Weekly Project

Compute your portfolio's basic risk metrics.

1
List your (demo) portfolio holdings and weights.
2
Estimate the volatility of each and the portfolio.
3
Estimate the worst realistic drawdown.
4
Write 2 sentences on whether that drawdown is survivable for you.
Open tool →
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