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🎯 Diversification – Why Concentration Increases Risk

Diversification is spreading investments across different assets, sectors, and geographies to reduce risk. The principle: don't put all eggs in one basket. Concentration in single company, sector, or country means one failure destroys entire portfolio. Diversification reduces this specific risk while maintaining growth potential. Most important free lunch in investing - lowers volatility without sacrificing long-term returns.

Key Point: Diversification: spreading investments to reduce concentration risk. Single asset dangerous: company bankruptcy, sector decline, country crisis wipes out wealth. Example: all savings in one company stock - if company fails, lose everything despite market growing. Property vs shares vs cash: different characteristics, move differently, owning mix reduces overall volatility. Property stable but illiquid, shares volatile but liquid, cash safe but inflation erodes. Balanced portfolio 40% property, 40% shares, 20% cash performs more consistently. Sector concentration: NZ investor heavy in banks (ANZ, Westpac, BNZ) - banking crisis affects entire portfolio simultaneously. Geographic concentration: only NZ assets vulnerable to NZ-specific events (earthquake, policy, recession). Global diversification protects. NZ scenario: Robert held only NZ bank shares, 2008 GFC hit banks hard, lost 50% while diversified portfolios lost 25%. Lesson: don't concentrate in single sector even if familiar. Diversification checklist: own multiple assets, spread across sectors, include international exposure, rebalance annually. "Don't put all eggs in one basket" - oldest investment wisdom, still most important.

What Is Diversification?

Definition:

Diversification is the practice of spreading investments across different assets, companies, sectors, and regions to reduce risk. When one investment performs poorly, others may perform well, smoothing overall returns.

The Core Principle:

"Don't put all your eggs in one basket"

  • If carry all eggs in one basket and drop it: lose everything
  • If spread across multiple baskets and drop one: lose only portion
  • Same logic applies to investments

Why Diversification Works:

  • Different investments don't move in lockstep
  • When shares fall, bonds may rise
  • When property stagnates, shares may boom
  • Losses in one area offset by gains in another
  • Reduces portfolio volatility (smooths ride)

Diversification Dimensions:

1. Asset class diversification:

  • Property, shares, bonds, cash, commodities
  • Each behaves differently

2. Individual holding diversification:

  • Within shares: own 20-30 companies not just 1-2
  • Within property: multiple properties not one

3. Sector diversification:

  • Technology, healthcare, finance, energy, consumer
  • Different sectors perform differently

4. Geographic diversification:

  • NZ, Australia, US, Europe, Asia, emerging markets
  • Different countries face different challenges

The Mathematics:

Diversification reduces specific risk (risk unique to individual investments) but not systematic risk (market-wide risk that affects everything).

Example: Two-Stock Portfolio

Scenario A - Concentrated (both tech stocks):

  • Stock A: +20% year
  • Stock B: +18% year
  • Tech sector booms: Portfolio +19%
  • Tech sector crashes -40%: Portfolio -40%
  • High volatility

Scenario B - Diversified (tech + utility):

  • Tech stock: +20% (boom) or -40% (crash)
  • Utility stock: +5% (stable)
  • Tech boom: Portfolio +12.5% (lower gain)
  • Tech crash: Portfolio -17.5% (lower loss)
  • Lower volatility, more consistent

⚠️ Single Asset Exposure and Asset Classes

Why Single Asset Exposure Is Risky

Concentration Risk - Company Level:

Example: All savings in employer stock

  • Work for company X
  • Invest all savings in company X shares
  • Company faces crisis: Job + investments both gone
  • Double exposure: income and wealth tied to same entity

Real example: Enron employees (2001):

  • Employees held retirement savings in Enron stock
  • Company collapsed (fraud)
  • Lost jobs AND life savings simultaneously
  • Could have been prevented by diversification

Company-Specific Risks:

  • Bankruptcy (company fails)
  • Fraud/scandal (management issues)
  • Product failure (market rejection)
  • Competition (disruption)
  • Regulatory changes (affects business model)

Any single company can fail regardless of how strong it seems. Diversification protects against this.

Property vs Shares vs Cash

Characteristics of Each:

Property (Real Estate):

  • Returns: 5-8% annually long-term (NZ)
  • Volatility: Low to moderate (slow changes)
  • Liquidity: Very low (3-6 months to sell)
  • Income: Rental yield 3-5%
  • Inflation: Good hedge (prices rise with inflation)
  • Risk: Illiquidity, location-specific, maintenance

Shares (Equities):

  • Returns: 7-10% annually long-term
  • Volatility: High (can swing 20-30% yearly)
  • Liquidity: High (sell in days)
  • Income: Dividends 2-4%
  • Inflation: Good hedge (company profits rise)
  • Risk: Volatility, can lose 50%+ in crashes

Cash/Bonds:

  • Returns: 2-4% annually
  • Volatility: Very low (stable)
  • Liquidity: Immediate
  • Income: Interest payments
  • Inflation: Poor (real returns often negative)
  • Risk: Inflation erosion, low returns

Why Own Multiple Asset Classes:

Different performance in different conditions:

Economic Condition Property Shares Cash/Bonds
Boom (growth) Strong Very Strong Weak
Recession Weak Weak Strong (safety)
High inflation Good (prices rise) Mixed Poor (eroded)
Low inflation Moderate Strong Good

No single asset performs well in all conditions. Diversification ensures something working in every environment.

Example Portfolio:

Concentrated (all property):

  • $500k in single investment property
  • Property market crashes -30%: Portfolio -30%
  • Property booms +30%: Portfolio +30%
  • High volatility, vulnerable to property-specific risks

Diversified (40/40/20):

  • $200k property (40%)
  • $200k shares (40%)
  • $100k cash/bonds (20%)

Property crashes -30%:

  • Property: $200k → $140k (-$60k)
  • Shares: Often rise when property falls → $220k (+$20k)
  • Cash: Stable $100k
  • Portfolio: $500k → $460k (-8%)

Diversification reduced loss from -30% to -8% by spreading across uncorrelated assets.

🏭 Sector and Geographic Diversification

Sector Concentration Risk

What Is Sector Concentration:

Investing heavily in one industry sector (banking, technology, energy). When that sector struggles, entire portfolio suffers.

NZ Context - Banking Sector Concentration:

Common NZ investor holdings:

  • ANZ shares
  • Westpac shares
  • ASB (Commonwealth Bank)
  • BNZ (National Australia Bank)

Feels diversified (4 different banks) but all banking sector - highly correlated. When banking sector hit, all fall together.

Sector Risks:

Banking sector:

  • Financial crisis (2008 GFC)
  • Regulation changes
  • Interest rate changes
  • Bad loan provisions

Technology sector:

  • Dot-com crash (2000)
  • Rapid obsolescence
  • High valuations collapse

Energy sector:

  • Oil price crashes
  • Renewable transition
  • Geopolitical events

Proper Sector Diversification:

Spread across sectors:

  • 15-20% Financials (banks, insurance)
  • 15-20% Technology
  • 15% Healthcare
  • 15% Consumer (retail, food)
  • 10% Industrials
  • 10% Energy/Materials
  • 15% Other sectors

No single sector dominates - protects against sector-specific crashes.

Geographic Diversification

Why Geographic Concentration Risky:

NZ-only portfolio vulnerable to:

  • Natural disasters (earthquakes)
  • NZ-specific policy changes
  • Small market size (limited companies)
  • Currency risk (NZD weakness)
  • Economic downturns

NZ Market Limitations:

  • NZX small: ~150 listed companies
  • Dominated by few sectors (utilities, property, banks)
  • Missing entire industries (tech giants, large pharma)
  • Represents <1% of global market capitalization

Benefits of Global Diversification:

Access to growth everywhere:

  • US technology boom
  • Asian manufacturing growth
  • European luxury brands
  • Emerging market development

Currency diversification:

  • NZD falls: international investments rise in NZD terms
  • Natural hedge against currency weakness

Example allocation:

  • 30% NZ (home bias - easier, familiar)
  • 30% Australia (similar, accessible)
  • 25% US (largest market, tech giants)
  • 10% Europe
  • 5% Asia/Emerging markets

👤 NZ Scenario and Diversification Checklist

NZ Scenario: Robert's Bank Share Concentration

Background (2007):

  • Robert: 55, accountant in Wellington
  • Lifetime saver, built $400k investment portfolio
  • Conservative investor, avoided "risky" shares
  • Believed banks were "safe as houses"

Robert's Portfolio (Pre-GFC):

  • ANZ shares: $120,000 (30%)
  • Westpac shares: $100,000 (25%)
  • National Australia Bank: $80,000 (20%)
  • Commonwealth Bank (ASB parent): $80,000 (20%)
  • Cash: $20,000 (5%)
  • Total: $400,000

Robert's Rationale:

  • "Banks always make money"
  • "They're too big to fail"
  • "Dividends are reliable income"
  • "I understand banking - I'm an accountant"
  • Felt diversified (4 different banks)

The 2008 Global Financial Crisis:

Banking sector devastated:

  • ANZ: Fell 52% (peak to trough)
  • Westpac: Fell 48%
  • NAB: Fell 55%
  • CBA: Fell 47%

Robert's portfolio impact:

  • ANZ: $120k → $58k (-$62k)
  • Westpac: $100k → $52k (-$48k)
  • NAB: $80k → $36k (-$44k)
  • CBA: $80k → $42k (-$38k)
  • Cash: $20k (stable)
  • Total: $400k → $208k (-48%)

Comparison - Diversified Portfolio:

If Robert had been diversified:

  • 20% Banks: $80k → $42k (-$38k)
  • 20% Healthcare: $80k → $72k (-10% - defensive)
  • 20% Consumer: $80k → $60k (-25%)
  • 20% International: $80k → $64k (-20%)
  • 20% Cash/Bonds: $80k → $80k (0%)
  • Total: $400k → $318k (-21%)

Diversified portfolio lost 21% vs Robert's 48% - half the damage from same crisis.

Robert's Recovery:

  • Held through crisis (didn't panic sell - good)
  • Banks recovered by 2012
  • Portfolio back to $380k by 2014
  • But lost years of growth and endured enormous stress
  • Sleepless nights, health impacts, retirement delayed

Robert's Learning:

  • "4 banks is NOT diversification - all banking sector"
  • "Familiar doesn't mean safe"
  • "Even 'safe' sectors can collapse"
  • "Should have spread across sectors and countries"
  • Now holds: 20% NZ banks, plus healthcare, tech, consumer, international
  • More boring portfolio but sleeps better

Diversification Checklist

Asset Class Diversification:

  • ☐ Do I own multiple asset classes? (property, shares, bonds/cash)
  • ☐ Current allocation:
    • Property: ____%
    • Shares: ____%
    • Bonds/Cash: ____%
  • ☐ Is any single asset class > 70%? (consider reducing)

Individual Holdings:

  • ☐ Within shares: Do I own at least 20-30 companies?
  • ☐ Is any single company > 10% of portfolio?
  • ☐ Am I heavily concentrated in employer stock?
  • ☐ Consider: Use managed funds/ETFs for instant diversification

Sector Diversification:

  • ☐ Spread across sectors:
    • Financials: ____%
    • Technology: ____%
    • Healthcare: ____%
    • Consumer: ____%
    • Other: ____%
  • ☐ Is any single sector > 30%?
  • ☐ Am I too heavy in NZ's dominant sectors (banks, utilities)?

Geographic Diversification:

  • ☐ Spread across countries/regions:
    • NZ: ____%
    • Australia: ____%
    • US: ____%
    • Europe: ____%
    • Asia: ____%
  • ☐ Is NZ-only investment > 50%? (consider international exposure)
  • ☐ Do I have currency diversification?

Red Flags:

  • ☐ All investments in one company (extreme risk)
  • ☐ All investments in one sector (Robert's mistake)
  • ☐ All investments in NZ only (country risk)
  • ☐ Employer stock > 10% of portfolio (job + wealth tied together)
  • ☐ Haven't reviewed diversification in 2+ years

Action Steps:

  • ☐ Review current holdings and calculate percentages
  • ☐ Identify concentration risks
  • ☐ Rebalance toward targets over 6-12 months
  • ☐ Consider low-cost index funds for easy diversification
  • ☐ Set calendar reminder to review annually

Final insight: Diversification spreads investments to reduce concentration risk - don't put all eggs in one basket. Single asset exposure dangerous: company failure, sector decline, country crisis wipes out wealth. Property vs shares vs cash have different characteristics, move differently, owning mix reduces volatility. Property stable but illiquid, shares volatile but liquid, cash safe but inflation erodes - balanced portfolio performs consistently. Sector concentration: NZ investor heavy in banks vulnerable when banking crisis hits all simultaneously (Robert lost 48% vs diversified 21%). Geographic concentration: NZ-only portfolio vulnerable to NZ-specific events, missing global growth opportunities. NZ represents <1% global market. Robert scenario: $400k all in NZ bank shares (ANZ, Westpac, NAB, CBA), felt diversified but all banking sector, 2008 GFC hit banks hard, lost 48% while diversified lost 21%, learned 4 banks ≠ diversification. Checklist: own multiple assets, spread across sectors (no sector >30%), include international (NZ <50%), avoid employer stock concentration, rebalance annually. Diversification is "only free lunch in investing" - reduces risk without sacrificing long-term returns.

🎯 Test Your Knowledge

Quiz on Diversification

1. Diversification is:
Investing in many of the same type of asset
Spreading investments across different assets, sectors, and regions to reduce risk
Only buying expensive investments
Avoiding all risk
2. Robert held shares in ANZ, Westpac, NAB, and CBA. This is:
Well diversified
Poorly diversified - all banking sector (sector concentration)
Risk-free
Perfect portfolio
3. During 2008 GFC, Robert's concentrated bank portfolio lost:
10%
21%
48% (while diversified portfolio lost 21%)
Nothing
4. NZ represents approximately what % of global market capitalization:
20%
5%
<1% (very small)
50%
5. Property, shares, and cash perform:
Identically in all conditions
Differently in different economic conditions - owning mix reduces volatility
Shares always best
Cash always safest long-term
6. Diversification reduces:
All risk completely
Specific risk (individual company/sector) but not systematic risk (market-wide)
Returns
Nothing
7. Investing heavily in employer stock is risky because:
Employer stocks always fail
Job and investments both tied to same company - double exposure
It's illegal
No risk at all
8. Recommended number of individual companies in a diversified share portfolio:
1-5
20-30 (or use index funds)
100+
Just 1 is enough
9. Geographic diversification means:
Only investing in Auckland
Spreading investments across multiple countries/regions
Avoiding international markets
Only NZ investments
10. Diversification is called "the only free lunch in investing" because:
It costs nothing
It reduces risk without sacrificing long-term returns
It guarantees profits
It eliminates all risk

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