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Module 7 · L10 of 12 ~25 min MST-12-S2-02 ⚡ +50 XP available

Investment Strategies

You inherit $50,000. Should you put it in a savings account at 4%, buy shares expected to return 8%, pay down your mortgage at 5%, or split it across all three? There is no single right answer, the best choice depends on your goals, time horizon, risk tolerance, and the broader economic environment. Investment strategy is the art and science of allocating money across different options to achieve the best risk-adjusted return.

Today's hook, You have $10,000. Option A: term deposit at 4.5% guaranteed. Option B: shares with expected 8% return but possible loss. Option C: extra mortgage repayment at 5.2%. How would you decide? What information do you need?
0/5QUESTS

Get oriented

Recall what you already know, meet the key ideas and settle the terms.

Worksheets

Practise this lesson

Three printable worksheets that build from foundations to mastery, or build your own from any module’s questions.

Build Foundations & guided practice Apply Application practice Master Mastery challenge Build custom Build your own from any module question
01
Recall, your gut answer first
+5 XP warm-up

You have $10,000. Option A: term deposit at 4.5% guaranteed. Option B: shares with expected 8% return but possible loss. Option C: extra mortgage repayment at 5.2%. How would you decide? What information do you need?

Before reading on write your gut reasoning. We will revisit this at the end of the lesson.

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02
Key ideas for this lesson
reference

Investment decisions are driven by four factors: return, risk, time horizon, and the impact of inflation. Two ideas tie almost every comparison together.

Real return: $\text{Real return} = \text{Nominal return} - \text{Inflation rate}$. This is what your money's purchasing power actually grows by, not just the headline number on the statement.

Risk-return trade-off: Higher potential returns always require accepting higher risk. There is no free lunch in investing, if an option seems to offer high returns with no risk, re-examine the assumptions.

Real return is the nominal return adjusted for inflation.
Always compare investments using real (after-inflation) returns when your goal is to preserve or grow purchasing power over time.
Risk-return spectrum
Cash and term deposits: low risk, low return. Shares and property: higher risk, higher expected return. Always match risk to your time horizon.
Diversification
Spreading investments across different asset classes reduces overall portfolio risk without proportionally reducing expected return.
Time horizon
Long horizons (10+ years) allow higher-risk investments, as short-term volatility averages out. Short horizons require safer, more liquid assets.
03
What you will master
Know

Key facts

  • The risk-return relationship
  • The diversification principle
  • Real return vs nominal return
Understand

Concepts

  • Why time horizon matters for investment choice
  • How inflation erodes purchasing power
  • The trade-off between liquidity and return
Can do

Skills

  • Calculate nominal and real future values
  • Compare multiple investment options quantitatively
  • Assess risk-adjusted choices for different scenarios
04
Key terms
Nominal returnThe percentage return before adjusting for inflation, the headline figure reported by a bank or fund.
Real returnNominal return minus the inflation rate. Represents the actual growth in purchasing power.
DiversificationSpreading investments across different asset classes, industries, or geographies to reduce overall risk.
VolatilityThe degree to which an investment's returns vary from year to year, a measure of risk.
LiquidityHow quickly and easily an investment can be converted to cash without significant loss of value.
Time horizonHow long until you need to access the invested money. Longer horizons allow higher-risk strategies.

Compare more than the rate

Weigh fees, compounding frequency and access alongside the headline rate.

05
Comparing investments, more than just the rate
core concept

When comparing investments, you must consider all of these dimensions, not just the headline rate:

  • Expected return: The average annual growth rate
  • Risk/volatility: How much returns vary year to year
  • Liquidity: How quickly you can access your money
  • Time horizon: How long until you need the money
  • Tax implications: Interest, dividends, capital gains taxed differently
  • Inflation: The real purchasing power of returns

Real return formula:

$$\text{Real return} = \text{Nominal return} - \text{Inflation rate}$$

Examples:

  • 6% nominal return with 3% inflation $\Rightarrow$ 3% real return
  • 4.5% term deposit with 2.5% inflation $\Rightarrow$ 2% real return
  • 7.5% shares with 2.5% inflation $\Rightarrow$ 5% real return
Paying down a mortgage is an investment: Paying an extra $\$1000$ on a 5.4% mortgage saves $\$54$/year in interest, a guaranteed, risk-free, after-tax return of 5.4%. This is often better than a term deposit once tax on interest income is considered.

Comparing investments requires looking beyond the interest rate: consider compounding frequency (affects EAR), term length (affects total return), fees and charges (reduce net return), and whether capital is accessible when needed.

Pause, copy the four investment comparison factors: (1) interest rate (or EAR for fair comparison); (2) compounding frequency; (3) fees and charges (reduce net return); (4) liquidity (can you access the money when needed) into your book.

Quick check: A term deposit earns 5.5% p.a. When inflation is 2.8%, the real return is:

Weigh risk, return and time

See how diversification and the time horizon change which option suits.

06
Risk and return, diversification, and time horizon
core concept

Comparing investments requires looking at rate, compounding frequency (EAR), term, fees, and liquidity, all quantitative. The broader principles that underpin every financial decision are qualitative: higher potential return always comes with higher risk (the risk-return trade-off), and spreading investments across different asset classes (diversification) reduces risk without necessarily reducing expected return.

The risk-return spectrum:

Investment Typical return Risk level Liquidity
Savings account2–4%Very lowVery high
Term deposits4–5%LowLow (locked)
Bonds4–6%Low-mediumMedium
Property5–8%MediumVery low
Shares (ETF)7–10%Medium-highHigh
CryptocurrencyHighly variableVery highHigh

Diversification: A portfolio of 100% shares might return 8% on average but could lose 30% in a bad year. A diversified portfolio (50% shares, 30% bonds, 20% property) might return 6.5% on average but only lose 12% in a bad year. The diversified portfolio sacrifices some return for significantly less risk.

Time horizon:

  • Short term (0–3 years): Safety first, savings accounts, term deposits
  • Medium term (3–10 years): Balanced, mix of bonds and shares
  • Long term (10+ years): Growth-focused, mostly shares and property
Why time horizon matters mathematically: Over short periods, shares are volatile and can produce large losses. Over long periods, the mathematics of averaging means good years outweigh bad. A 30-year-old investing for retirement can afford a 30% loss; a 65-year-old drawing down savings cannot.

Risk and return are positively related: higher potential returns come with higher risk. Diversification, spreading investments across different asset classes, reduces risk without necessarily reducing expected return.

Pause, copy the risk-return trade-off (higher potential return = higher risk) and the diversification principle (spreading investments across asset classes reduces risk without necessarily reducing expected return) into your book.

True or false: A risk-averse investor with a 25-year time horizon should always choose a term deposit over shares, because term deposits are safer.

Work the comparison activities

Follow the worked investment comparisons end to end.

Worked examples · reveal each step

PROBLEM 1 · COMPARING TWO INVESTMENTS OVER 8 YEARS

$20,000 to invest. Option A: 4.5% term deposit. Option B: diversified shares expected to return 7.5% but with possible 20% loss in any year. Inflation = 2.5%. Time horizon = 8 years. Calculate real returns and expected final values. Make a recommendation.

1
Option A real return $= 4.5\% - 2.5\% = 2.0\%$. Option B real return $= 7.5\% - 2.5\% = 5.0\%$.
Subtract the inflation rate from each nominal return
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PROBLEM 2 · SUPER vs ETF vs MORTGAGE

A 25-year-old contributes $\$500$/month to super (plus $\$575$/month employer at 7.2% p.a.). As an alternative, they invest that same $\$500$/month after tax (30% marginal rate) in an ETF at 8% p.a. Compare balances at age 65.

1
Super total monthly $= 500 + 575 = \$1075$. $n = 40 \times 12 = 480$ months. $r = 0.072/12 = 0.006$.
Add employee and employer contributions; convert to monthly parameters
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Beyond the syllabus. Comparing savings accounts, term deposits, shares and property on risk, liquidity, cost and time horizon is core. Detailed superannuation tax modelling, ETFs, salary sacrifice and portfolio theory are extension — exam questions stay with the core comparison criteria.
08
Investment comparison, worked activities
core concept

Risk-return and diversification are conceptual principles, but an exam comparison question requires a calculation-based answer. Calculate the final value or total return for each option under identical conditions (same initial investment, same period, same compounding basis), state the dollar difference explicitly, then justify the recommendation with a financial principle such as compounding frequency, risk level, or liquidity needs.

How to compare investments systematically:

  1. Calculate the nominal future value for each option: $FV = PV(1+r)^n$ for lump sums, or $FV = PMT \times \dfrac{(1+r)^n - 1}{r}$ for regular contributions.
  2. Calculate the real future value: use the real return rate instead of the nominal rate.
  3. Consider the worst-case scenario for risky assets.
  4. Factor in liquidity, tax, and access restrictions.
  5. Match to the investor's time horizon and risk tolerance.
Key insight: The best investment is not always the one with the highest nominal return. It is the one that best matches your goals, timeline, risk tolerance, tax position, and need for liquidity. A 60-year-old retiree and a 25-year-old earner may have completely different optimal strategies for the same $50,000.

To compare two investments: calculate the final value or total return for each under the same conditions. Express difference in dollars (not just percentages). State which is better and why, referencing rate, compounding, and term.

Pause, copy the three-part comparison method: (1) calculate final value for each option under identical conditions; (2) state the dollar difference; (3) give a reason referencing a financial principle (EAR, risk, compounding) into your book.

Fill the gap: A 6% nominal return with 2.5% inflation gives a real return of %. After 10 years, $\$30,000$ invested at 6% p.a. gives a nominal future value of $\$$ (round to nearest dollar).

Avoid the inflation traps

Stop comparing nominal rates without adjusting for inflation.

Common errors · the 3 traps that cost marks

Trap 01
Comparing nominal rates without adjusting for inflation
A 5% savings account with 4% inflation gives only 1% real return, barely preserving wealth. A 7% share portfolio with 2% inflation gives 5% real return, growing wealth rapidly. Always compare using real returns for purchasing-power questions.
Trap 02
Ignoring time horizon when assessing risk
Shares can lose 30% in a year, but over 20 years Australian shares have averaged ~8%+ p.a. Using short-term volatility to reject shares for a 20-year investment is mathematically incorrect, the relevant risk is the chance of underperforming over the full horizon, not within a single year.
Trap 03
Treating diversification as reducing return by the same amount as risk
Diversification reduces risk more than it reduces return because different assets are not perfectly correlated, when shares fall, bonds often rise. The diversified portfolio is not simply the average of its parts.

Match each term to its correct description:

  • Real return
  • Diversification
  • Liquidity
  • Time horizon
  • How quickly an investment can be converted to cash
  • How long until the money is needed
  • Nominal return minus inflation rate
  • Spreading investments to reduce risk

Drill it and revisit

Run the drill, then return to your opening answer and name what has changed.

Quick-fire practice · 2 activities

1

Calculate real returns for: (a) 3.5% savings with 2% inflation, (b) 7% shares with 2.5% inflation, (c) 5% property with 3% inflation. Then find the nominal FV of $30,000 invested for 10 years at (a) 6% and (b) 4%.

2

A retiree has $\$500,000$. Why should they NOT put it all in shares despite higher expected returns? A 25-year-old with $\$500,000$, should they make the same decision? Explain using time horizon and risk tolerance.

Top 3 list: Name THREE factors (beyond the nominal interest rate) that should influence an investment decision. For each, explain with a concrete example how it affects the choice.

09
Revisit your thinking

The decision depends critically on time horizon and risk tolerance. The term deposit (4.5%) is safe but barely beats inflation. The mortgage repayment (5.2%) is a guaranteed 5.2% return with no tax, excellent if you value certainty. Shares (8% expected) offer the highest long-term real return but with volatility.

For money needed within 3 years: term deposit or mortgage is safer. For money not needed for 10+ years: shares historically outperform. Many advisors recommend splitting, some in safe assets for short-term needs, some in growth assets for long-term wealth building.

What has changed in your understanding? What did you get right? What surprised you?

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Practise investment strategies

Answer the question bank, then write full short-answer responses.

01
Multiple choice
+5 XP per correct · +25 XP all-correct

Pick your answer, then rate your confidence. That tells the system what to drill next.

Q1. An investment earns 7.5% p.a. nominal return. With inflation at 3%, the real return is:

Q2. Paying an extra $5000 on a mortgage charging 5.4% p.a. is mathematically equivalent to:

Q3. A retiree needs income from their savings in the next 2 years. The most appropriate investment is:

Q4. A diversified portfolio holds 50% shares, 30% bonds, and 20% property. Compared to 100% shares, the diversified portfolio will typically have:

Q5. $25,000 invested for 6 years at 5% p.a. compounded annually. The future value is closest to:

02
Short answer
ApplyBand 42 marks

SA 1. (a) Calculate the real return on a 5.5% term deposit when inflation is 2.8%. (b) $25,000 invested for 6 years: compare a term deposit at 5% (guaranteed) vs shares at expected 8% (with possible 25% loss in year 1). Find the final values for both the best-case and worst-case share scenario. (c) Which would you choose for a 6-year time horizon, and why? (2 marks)

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ApplyBand 42 marks

SA 2. A couple has $40,000. They can: (A) pay down their mortgage at 5.4%, (B) invest in super at expected 7% (taxed at 15%), or (C) put in a savings account at 4%. Inflation is 2.5%. Compare the after-inflation, after-tax outcomes over 10 years and recommend. (2 marks)

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AnalyseBand 53 marks

SA 3. A 25-year-old earns $\$60,000$ and contributes $\$500$/month to super. Their employer contributes $\$575$/month. The super fund earns 7.2% p.a. compounded monthly. (a) Calculate the super balance at age 65. (b) As an alternative, the person diverts $\$400$/month of pre-tax income and invests what is left after tax at a 30% marginal rate, in an ETF at 8% p.a. compounded monthly. Calculate the balance at age 65. (c) Compare both options on return, liquidity, and risk. Make a recommendation, noting one limitation of your answer. (3 marks)

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Comprehensive answers (click to reveal)

MC 1, C: Real return = 7.5% − 3% = 4.5%.

MC 2, B: Extra mortgage repayment saves interest at the mortgage rate, a guaranteed, risk-free return of 5.4%.

MC 3, D: Short time horizon and need for liquidity require a low-risk, accessible investment.

MC 4, A: Diversification reduces both return and risk compared to 100% shares, but reduces risk more than proportionally.

MC 5, C: $25\,000 \times (1.05)^6 = 25\,000 \times 1.3401 = \$33\,503$.

SA 1 (2 marks): (a) 2.7% [0.5]. (b) TD = $\$33,503$; Shares best = $\$39,698$; Shares worst = $25,000 × 0.75 × (1.08)5 = $29,773 [1]. (c) Reasoned recommendation based on risk tolerance and time horizon [0.5].

SA 2 (2 marks): (A) Mortgage FV equivalent = 40,000 × (1.054)10 = $\$67,700$, real return 2.9% [0.5]. (B) Super after tax: 7% × 0.85 = 5.95%, real = 3.45%, FV = $\$70,200$ [0.5]. (C) Savings real 1.5%, FV = $59,210 [0.5]. Recommendation: Super has highest after-tax real return; mortgage is guaranteed [0.5].

SA 3 (3 marks): (a) $\$1075$/month, r=0.006, n=480. FV = $\$1,075$ × [(1.006)480−1]/0.006 ≈ $\$2,985,200$ [1]. (b) After-tax amount = $\$400$ × 0.70 = $\$280$/month. After-tax return = 8% × 0.70 = 5.6% p.a. ≈ 0.4667%/month. FV = $\$280$ × [(1.004667)480−1]/0.004667 ≈ $\$500,700$ [1]. (c) Super dominates mathematically ($\$3.0$M vs $501K) but is inaccessible until preservation age (~60). ETF is accessible anytime but produces far less due to tax. Recommendation: prioritise super, but maintain some liquid investments. Limitation: assumes rates remain constant over 40 years, which is unlikely [1].

Drill 1: Real: (a) 1.5%, (b) 4.5%, (c) 2%. FV at 6%: $53,725. FV at 4%: $44,407.

Drill 2: Retiree needs income soon, high volatility risk with no time to recover losses; needs liquidity. 25-year-old can absorb losses over decades; shares are appropriate for long-term wealth building.