20 Largest Companies in the FTSE 100

The FTSE 100 is the best-known measure of large companies listed in London, but it is a poor proxy for the domestic British economy. Many of its largest constituents earn the majority of their revenue outside the UK. Global energy, pharmaceuticals, mining, banking and consumer goods therefore have far more influence on the index than their share of British GDP might suggest.

FTSE Russell selects eligible companies from the London market and weights the index by investable market capitalisation. Free float matters, meaning strategic holdings that are not readily available to public investors are adjusted when index weights are calculated.

The FTSE 100 is unusually international

AstraZeneca sells medicines around the world. Shell and BP are global energy companies. HSBC and Standard Chartered have substantial Asian businesses. Unilever sells consumer products across dozens of markets, while Rio Tinto and Glencore are exposed to global commodity demand rather than only British industrial activity.

This international revenue base helps explain one of the FTSE 100's recurring market patterns. Sterling weakness can support reported earnings for companies that generate dollars, euros and other currencies overseas, even when the domestic UK economy is soft. A stronger pound can have the opposite translation effect.

Banks and commodities give the index a different character

Compared with the S&P 500 and Nasdaq-100, the FTSE 100 has less exposure to megacap technology and more exposure to financials, energy, mining and income-producing companies. That sector mix can make it lag during technology-led global rallies and outperform when commodity prices, interest margins or value stocks strengthen.

HSBC, Barclays and Lloyds give investors different forms of banking exposure. Shell and BP tie parts of the index to oil and gas markets, while Rio Tinto and Glencore bring iron ore, copper and other commodities into the benchmark. The FTSE 100 is therefore often more cyclical than a casual reading of the word blue chip might imply.

Dividend income is part of the index's appeal

Many large FTSE companies have mature businesses and established dividend policies. Energy, banking, telecoms and consumer staples have historically supplied a meaningful part of total shareholder return. The exact yield changes constantly with share prices and distributions, so investors should separate a company's dividend record from a single snapshot yield.

A high yield can also be a warning rather than a bargain. If the market expects profits or cash flow to fall, the share price may decline faster than the dividend has been cut, temporarily pushing the quoted yield higher. Balance-sheet strength and dividend cover matter more than the headline percentage alone.

What the largest FTSE companies tell investors

The index's top companies provide a concise map of London's public-market strengths: pharmaceuticals, banking, energy, mining, consumer brands and financial-market infrastructure. London has large technology businesses, but they do not dominate the benchmark in the way US technology groups dominate American indices.

That difference is useful for diversification. It is also why comparisons between the FTSE 100 and S&P 500 need to account for sector composition. Two national indices can produce very different returns even when their underlying economies grow at similar rates because the listed companies are exposed to different global profit cycles.