Portfolio Risk and Return: Part I
1. Characteristics of Major Asset Classes
Before we can build a house, we must understand our materials. In portfolio construction, our materials are asset classes. An asset class is a grouping of investments that exhibit similar characteristics and behave similarly in the marketplace.
We generally group these into three distinct categories based on their risk-return profiles.
Cash and Cash Equivalents
These are the bedrock. Think of Treasury bills or money market funds.
Return Profile: Low. In 2026, yields have stabilized, but they generally barely beat inflation.
Risk Profile: Extremely low. The standard deviation of returns is near zero.
Role: Liquidity and safety. This is the"sleeping well at night" portion of the portfolio.
Fixed Income (Bonds)
This is debt. You are the lender; the government or corporation is the borrower.
Return Profile: Moderate. The return comes from coupon payments and potential price appreciation if interest rates fall.
Risk Profile: Low to Moderate. It depends on the credit quality (will they pay you back?) and duration (how sensitive is the price to interest rate changes?).
Correlation: Historically, high-grade bonds often have a low or negative correlation with stocks, making them excellent diversifiers during economic slumps.
Equities (Stocks)
This is ownership. You own a slice of the business.
Return Profile: High. Over long periods, equities have historically provided the highest inflation-adjusted returns.
Risk Profile: High. Prices are volatile. A 20% drop in a year is not a bug; it is a feature of the equity market.
Role: Growth. This is the engine of the portfolio.
Alternative Investments
This bucket has grown significantly by 2026. It includes Real Estate, Private Equity, Commodities, and potentially Digital Assets.
Characteristics: These often suffer from illiquidity (you can't sell them quickly) and opacity (harder to analyze).
Role: Diversification. They often march to a different beat than stocks or bonds.
Example: Consider an investor holding only Tech Stocks (Equities). If the tech sector crashes, their wealth evaporates. If they add Government Bonds (Fixed Income), the bonds might hold steady or rise as investors flee to safety, cushioning the blow.
2. Risk Aversion and Portfolio Selection
Why do we demand higher