House Prices

Modern Portfolio Theory: Investor Fundamentals

This is the first in a series of informative articles on the basic principles of modern portfolio theory. Modern portfolio theory encapsulates the many assumptions made in investments including the long term horizon of investment, diversification, expected return, volatility and risk. In this article we introduce some of these basic principles.

Tuesday, April 20th 2004

In modern portfolio theory, statistical measures are used to describe investment characteristics of differing asset classes. The two primary measures are expected volatility and expected return. Modern portfolio theory essentially uses the fluctuations in expected return to determine the expected volatility of an investment.

Expected return is simply the performance of an investment that you are likely to receive over a long time horizon. It is calculated using the range of possible returns adjusted for the probability of each occurring. For example, over a two-year period, you may expect equities to return 12 per cent in the first year and 6 per cent in the second. Therefore the expected return, or average return, is 9 per cent (12+6/2=9). Although equity returns may fluctuate from 25 per cent to -25 per cent over the long term, you would still expect that your return to revert to the expected return.

Read More - Opens in a new window

Most Read

Unity First Home Buyer special 3.99
SBS FirstHome Combo 3.99
ICBC 4.25
TSB Special 4.39
Co-operative Bank - First Home Special 4.39
SBS Bank Special 4.49
Unity Special 4.49
ANZ Special 4.49
Westpac Special 4.49
Kiwibank Special 4.49
Co-operative Bank - Owner Occ 4.49
Kainga Ora 4.49
ICBC 4.59
Nelson Building Society 4.67
Unity Special 4.69
ANZ Special 4.69
BNZ - Std 4.69
Wairarapa Building Society 4.79
Westpac Special 4.89
SBS Bank Special 4.89
Kiwibank Special 4.89
Co-operative Bank - Owner Occ 4.89
ICBC 4.99
Kainga Ora 5.15
Westpac Special 5.49
ASB Bank 5.69
TSB Special 5.69
BNZ - Std 5.69
SBS Bank Special 5.69
Co-operative Bank - Owner Occ 5.69
AIA - Go Home Loans 5.69
Kiwibank Special 5.79
China Construction Bank 5.99
SBS FirstHome Combo 3.29
AIA - Back My Build 3.34
SBS Construction lending for FHB 3.74
CFML 321 Loans 3.95
Co-operative Bank - Owner Occ 4.99
Co-operative Bank - Standard 4.99
Heartland Bank - Online 5.30
ICBC 5.39
Kiwibank - Offset 5.65
Kiwibank 5.65
Kainga Ora 5.69

More Stories

Thursday, February 19th 2026

RBNZ expects slower house price growth in the current recovery

The Reserve Bank thinks house prices will rise at a much slower pace during the current recovery than they have in past cycles.

Wednesday, January 07th 2026

Queenstown not off the radar for first home buyers

First home buyers are not being deterred by Queenstown’s soaring house prices.

Record levels of first home buyers taking out low deposit loans

Tuesday, December 23rd 2025

Record levels of first home buyers taking out low deposit loans

About half of all first home buyer lending has been done at a less than 20% deposit in recent months.

Buyers sitting on the sidelines in best time to buy in a decade

Thursday, December 04th 2025

Buyers sitting on the sidelines in best time to buy in a decade

Stable house prices, low interest rates and plenty of houses to choose from are still not enticing buyers.