The FTSE 100 (pronounced "Footsie") is an index that tracks the 100 largest companies listed on the London Stock Exchange, ranked by market capitalisation. Market capitalisation is simply the total value of a company's shares — calculated by multiplying the share price by the number of shares in existence.
The index is maintained by FTSE Russell, a subsidiary of the London Stock Exchange Group. It was launched on 3 January 1984 with a base level of 1,000 points. When people say "the FTSE is at 8,200," they're referring to the current level of this index relative to that original starting point.
Think of it as a scoreboard. When the biggest UK companies are doing well and their share prices rise, the FTSE 100 goes up. When they struggle, it goes down.
What Companies Are in the FTSE 100?
The FTSE 100 includes household names that most people in the UK interact with daily. Companies like Shell, AstraZeneca, HSBC, Unilever, and BP are typically among the largest by market cap. The index spans a wide range of sectors including banking, energy, pharmaceuticals, consumer goods, and mining.
One important thing to understand is that the FTSE 100 is weighted by market capitalisation. This means larger companies have a bigger influence on the index's movement. If Shell's share price moves 2%, it has a much greater impact on the FTSE 100 than a smaller constituent moving by the same percentage.
FTSE 100 vs FTSE 250: What's the Difference?
The FTSE 250 tracks the next 250 companies by market cap after the top 100. While the FTSE 100 is dominated by large multinational corporations (many of which earn most of their revenue overseas), the FTSE 250 tends to be more focused on the UK domestic economy.
This is an important distinction. When people say "the UK market is up," the FTSE 100 might not tell the full story. Because many FTSE 100 companies are global, the index is heavily influenced by the strength of the US dollar, oil prices, and international events. The FTSE 250 often gives a better picture of how the UK economy itself is performing.
Together, the FTSE 100 and FTSE 250 form the FTSE 350, which covers the vast majority of the UK's publicly traded market value. You can compare stocks from both indices side by side using our comparison tool.
What Makes the FTSE 100 Move?
Several factors drive the FTSE 100 up or down on any given day. Company earnings reports are one of the biggest movers — when a major constituent like AstraZeneca beats profit expectations, it can push the whole index higher. Economic data matters too: interest rate decisions from the Bank of England, inflation figures, employment data, and GDP growth all feed into investor sentiment.
Global events play a significant role as well. Because so many FTSE 100 companies operate internationally, events like US Federal Reserve decisions, geopolitical tensions, or commodity price swings can move the index even when there's no UK-specific news. Currency movements are another factor — a weaker pound tends to boost the FTSE 100 because it increases the sterling value of overseas earnings.
You can stay on top of these movements with our daily market briefing, which covers key movers, economic events, and technical levels every trading day.
How Can You Invest in the FTSE 100?
There are several ways to get exposure to the FTSE 100. The most common for beginners is through an index tracker fund or ETF (Exchange Traded Fund) that replicates the index. These funds automatically hold shares in all 100 companies in the right proportions, so you get instant diversification without having to pick individual stocks.
Popular FTSE 100 trackers include the iShares Core FTSE 100 ETF and the Vanguard FTSE 100 Index Fund. These are available through most UK brokers and can be held inside a Stocks and Shares ISA for tax-free growth.
Alternatively, you can invest in individual FTSE 100 companies directly. This gives you more control but requires more research. Our stock screener lets you filter FTSE companies by key metrics like P/E ratio, dividend yield, and market cap to help narrow down your choices. If you want to go deeper on a specific company, our comparison tool lets you stack stocks side by side across multiple data points.
Why the FTSE 100 Matters to You
Even if you're not actively trading, the FTSE 100 affects your life. If you have a workplace pension, there's a good chance a portion of it is invested in FTSE 100 companies. The index's performance influences interest rates, the value of the pound, and the broader economic confidence that affects everything from house prices to job security.
For active investors and traders, understanding the FTSE 100 is foundational. It's the benchmark against which UK fund managers measure their performance, and it sets the tone for market sentiment each day. Knowing what drives the index helps you make more informed decisions about your own portfolio.
Start Tracking the FTSE 100
ChartsView gives you free tools to follow the FTSE 100 and its constituent stocks in real time. Use our stock screener to filter FTSE 100 companies by the metrics that matter to you, compare any stocks head to head, or track your favourites in your free portfolio. If you're interested in what other traders think about the market, check out our share tips leaderboard to see community picks with transparent track records.
New to all this? Our trading glossary explains every term you'll encounter, from "market cap" to "dividend yield" and beyond.