Sectors, Styles and the Business Cycle

“The market” is really a mosaic of very different businesses. A chipmaker, a utility, a bank and a food company react entirely differently to interest rates, oil prices or a recession. Knowing these differences helps you understand why the index moves – and what’s actually happening in your own portfolio.

The eleven sectors#

MSCI and S&P created the Global Industry Classification Standard (GICS), used worldwide. It defines eleven sectors:

Sector weights differ enormously between indices. In the S&P 500, information technology together with the big internet platforms makes up a very large share; the UK’s FTSE 100 leans towards energy, materials, banks and consumer staples; Germany’s DAX towards industrials, financials and autos.

Cyclical or defensive?#

Cyclical companies earn a lot in good times and little in bad ones. People buy cars, machinery, chemicals, hotel stays and luxury goods when things are going well and postpone them when they’re not. Their profits – and share prices – swing with the economy.

Defensive companies sell things people always need: food, medicine, electricity, toothpaste. Their profits are steadier. In recessions their shares usually fall less; in strong expansions they often lag.

Sector rotation through the cycle#

Because industries react differently to the economy, history shows typical patterns of which sectors led in which phase. The idea of sector rotation is to shift into the favoured industries in time.

Styles: growth, value and size#

Besides sectors, professionals classify stocks by investment style:

• Growth: companies with above-average revenue and earnings growth, usually highly valued. Many technology companies belong here. They are particularly sensitive to interest rates because their profits lie far in the future.
• Value: cheaply valued companies, often mature businesses with high dividends – banks, utilities, energy, industrials.
• Size: large caps, mid caps and small caps. Smaller companies swing more and are more sensitive to the economy.

Styles take turns leading, sometimes for many years. Growth dominated the 2010s; value led in 2022, when rising rates hit richly valued growth stocks especially hard. Whether value earns an excess return in the long run is one of the most interesting questions in finance research – more in the lesson on efficient markets and factors.

What it means for you#

• Know your exposure: a world or S&P 500 fund today is heavily tilted to technology and the US. A dividend fund leans towards financials, utilities and staples. If you combine them, know what weights result.
• Avoid doubling up: if you work for an oil company and also hold lots of energy stocks, you’re betting twice on one industry.
• Deliberate, not reactive: if you want to overweight a sector, do it from a long-term conviction, not because a theme is in the headlines.

Summary#

The stock market consists of eleven sectors with very different traits. Cyclical industries swing with the economy, defensive ones stay steadier. In the textbook, leadership rotates through the cycle; in practice, turning points are almost impossible to predict. Styles such as growth and value shape whole market eras. That completes Module 5 – you now know the big forces behind prices.