What it means
The traditional classes are equities, meaning shares in companies, fixed income, meaning bonds and other interest-paying loans, cash and cash equivalents, and real assets such as property and commodities. Alternatives form a looser fifth group covering private equity, infrastructure, hedge funds and private credit.
Each class has its own return pattern, income profile, liquidity and tax treatment. The grouping matters because of correlation, which simply means how closely two things move together.
Shares and government bonds have historically tended to move differently in a downturn, so holding both smooths the ride, whereas two technology shares move almost in step. A portfolio of twenty shares drawn from one sector is far less diversified than the number of holdings suggests.
Allocation is set against a purpose and a time horizon rather than a forecast. Money needed within a year belongs in cash, because capital stability matters more than return, while a pension pot thirty years away can carry equity volatility in exchange for higher expected growth.
Businesses apply the same logic in a treasury policy, splitting reserves between operating cash, short-dated deposits and longer-term investments. Every class carries a risk that deserves naming out loud.
Equities risk permanent capital loss and dividend cuts, bonds carry interest rate risk and credit risk, property is illiquid and expensive to transact, and commodities generate no income at all. Cash looks safe but steadily loses purchasing power whenever inflation runs above the deposit rate.
Portfolios drift, so allocation is a maintenance job rather than a single decision. If equities run hard, their share of the portfolio climbs above target and the risk profile changes without anyone choosing to take more risk.
Rebalancing back to target, either annually or whenever a class moves a set distance away, keeps the stated policy honest.
In practice
Real-world examples.
Example
A manufacturing business holds $2,000,000 of reserves and splits it by purpose: $400,000 in an instant access account for payroll, $1,000,000 in term deposits laddered across twelve months and $600,000 in a short-dated bond fund. That split is an asset allocation decision in all but name. When a machine fails unexpectedly, the instant access tranche covers the repair without disturbing the rest.
Example
A charity's investment committee reviews a portfolio that has drifted to 78% equities against a 65% target after a strong run. It sells enough shares to return to target and buys bonds with the proceeds. The trustees minute the rebalancing as evidence that they followed their own investment policy.
Example
A family office adds infrastructure and private credit to a portfolio that had only shares and bonds. The new classes bring income less tied to the share market, but they also lock capital away for several years. The committee therefore caps the illiquid allocation at 20% so that future commitments can still be met.
Formula
Calculation
The return of a multi-class portfolio is the weighted average of its parts:
Portfolio return = sum of (weight of each asset class x return of that asset class)
A $500,000 portfolio is held 60% in equities, 30% in bonds and 10% in cash. Over the year equities return 8%, bonds return 4% and cash returns 2%.
Equities: 60% x $500,000 = $300,000, earning 8% = $24,000
Bonds: 30% x $500,000 = $150,000, earning 4% = $6,000
Cash: 10% x $500,000 = $50,000, earning 2% = $1,000
Total gain = $24,000 + $6,000 + $1,000 = $31,000
Portfolio return = $31,000 / $500,000 = 6.2%
The same answer comes from the weights alone: (0.60 x 8%) + (0.30 x 4%) + (0.10 x 2%) = 4.8% + 1.2% + 0.2% = 6.2%.Case study
Seen in the real world.
Consider Marlowe Dental Group, an illustrative and fictional chain of clinics that had built up $3,000,000 of surplus cash. The founders put all of it into a single technology share fund because that fund had performed best over the previous three years.
When that market fell sharply in this fictional scenario, the fund dropped 35% and the reserve was worth $1,950,000 at exactly the moment the group needed $800,000 for a planned clinic fit-out. Selling enough units to raise the $800,000 turned part of the paper loss into a realised loss of roughly $430,000.
The group's illustrative adviser rebuilt the reserve around purpose instead of past performance: twelve months of committed spending in cash and term deposits, a bond allocation for the two-year horizon, and only the genuine long-term surplus in equities spread across several markets. The expected return fell, but the money was there when it was needed.
Watch out
Common mistakes.
- Confusing diversification across holdings with diversification across asset classes, so thirty shares in one sector are treated as a spread portfolio.
- Choosing an allocation from recent performance rather than from when the money will actually be needed.
- Treating cash as risk free, when inflation above the deposit rate erodes its real value every single year.
Questions
People also ask.
How many asset classes does a portfolio need?
There is no fixed number, and most private portfolios are well served by equities, bonds and cash, with real assets or alternatives added only when size and time horizon justify the complexity.
Is property an asset class in its own right?
Usually yes, split between direct property and listed property vehicles, which behave quite differently because one is illiquid and the other trades daily.
How often should a portfolio be rebalanced?
Commonly once a year, or whenever a class moves a set distance from its target, because frequent trading adds cost without adding much control.
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