5.6Lesson 5.6 · Module 5 — Risk and Return

Portfolio Risk Lab

Apply the complete Module 5 toolkit — return, volatility, correlation, beta, diversification — to a realistic portfolio decision for Cedar Ridge Education Reserve.

  • Inspect fictional return data
  • Calculate return, volatility, correlation, and beta
  • Compare two proposed portfolios
  • Stress-test idiosyncratic and systematic risks
  • Write a defensible analyst recommendation
Client mandate

Cedar Ridge Education Reserve

Cedar Ridge has asked you to evaluate two proposed portfolios built from three fictional securities. Your recommendation must satisfy the mandate below — the rules Cedar Ridge requires the portfolio to follow — and acknowledge the limits of the evidence.

  • Average monthly return ≥ 0.80% in the sample
  • Estimated portfolio beta ≤ 1.00
  • Avoid excessive concentration
  • Prefer meaningful diversification
  • Explain limitations of the 8-observation sample
5.6.1The data

Fictional monthly returns

Three fictional companies plus a market index, observed over eight months. All figures are illustrative.

MonthMarketAtlasNovaMeridian
12.01.24.02.0
2-1.0-0.4-3.01.0
33.01.86.0-1.0
4-2.0-0.8-5.00.0
54.02.17.03.0
6-3.0-1.0-6.0-1.0
71.00.72.02.0
82.01.13.01.0

Fictional monthly returns created for the OPS Portfolio Risk Lab.

Definition · Atlas Consumer
Stable, mature consumer business. Lower volatility, cyclical but less extreme than Nova.
Definition · Nova Technology
Highly cyclical with high operating leverage. The largest swings of the three in both directions.
Definition · Meridian Health
Less correlated with Atlas and Nova than they are with each other — the strongest diversifier in the set.
5.6.2The lab

Eight-round portfolio investigation

Work through the rounds in order. Completing a round unlocks the next.

Try itRound 1 · Data Inspection

Before computing anything, inspect the fictional return table. Form a visual hypothesis — then confirm or reject it with numbers in later rounds.

MonthMarketAtlasNovaMeridian
12.01.24.02.0
2-1.0-0.4-3.01.0
33.01.86.0-1.0
4-2.0-0.8-5.00.0
54.02.17.03.0
6-3.0-1.0-6.0-1.0
71.00.72.02.0
82.01.13.01.0

Fictional monthly returns created for the OPS Portfolio Risk Lab.

Which stock has the largest apparent swings?

Which pair appears to move together most closely?

Which stock appears most different from the other two?

Why are visual impressions insufficient?

Answer all four questions to continue.

5.6.3Module 5 synthesis

Connecting the full risk-and-return chain

1
Total return
Cash distribution + price change over a period.
2
Expected return
Probability-weighted average of possible future returns.
3
Arithmetic vs geometric
Arithmetic averages returns; geometric compounds them. Volatility widens the gap.
4
Volatility
Standard deviation measures dispersion of returns.
5
Covariance & correlation
How assets move together — the engine of diversification.
6
Diversification
Low correlation reduces portfolio variance below the weighted average of variances.
7
Systematic vs idiosyncratic
Market risk cannot be diversified away; firm-specific risk can.
8
Beta
Sensitivity to the market — the systematic-risk measure.
9
Empirical evidence
Real data confirms diversification, co-movement, and unstable estimates.
10
Analyst judgment
Numbers inform but do not replace a defensible recommendation.
5.6.4Common questions

Frequently asked

Try itMastery check
Pass with 4 of 6 correct

Answer all questions, then check your work. You can retry any time — mastery is based on correctness, not speed.

  1. 01

    Portfolio A beta ≈ ?

  2. 02

    Portfolio B beta ≈ ?

  3. 03

    Which portfolio satisfies the beta ≤ 1.00 mandate?

  4. 04

    Nova falls 40%. What is the approximate impact on Portfolio A?

  5. 05

    Atlas–Nova correlation ≈ ?

  6. 06

    Why does Meridian provide more diversification than simply adding more Atlas?

Lesson summary
  1. 1Portfolio return is a weighted average of asset returns.
  2. 2Portfolio volatility depends on correlations, not just individual volatilities.
  3. 3Beta measures market exposure; beta ≠ total risk.
  4. 4Lower correlation creates more diversification benefit.
  5. 5Portfolio A (concentrated) violates the beta ≤ 1.00 mandate.
  6. 6Portfolio B (diversified) satisfies the return, beta, and diversification criteria.
  7. 7Stress tests show both idiosyncratic and systematic risk matter.
  8. 8Eight observations cannot establish stable long-run parameters.
  9. 9A defensible recommendation requires evidence, comparison, risk analysis, and stated limitations.