January 3, 1984 the FTSE 100 Index Is Launched on the London Stock Exchange

On January 3, 1984, the FTSE 100 launched on the London Stock Exchange as Britain's definitive benchmark for tracking its 100 most highly capitalised blue-chip companies. It started at a base level of 1,000 points and used market capitalisation to measure performance across banking, retail, insurance, and industrials. It replaced outdated indexes that no longer reflected modern market activity. There's plenty more to uncover about how it works and what's changed over four decades.

Key Takeaways

• The FTSE 100 Index launched on 3 January 1984, tracking the 100 most highly capitalised blue-chip companies on the London Stock Exchange.
• It started with a base level of 1,000 points, providing a standardised benchmark for measuring UK equity market performance.
• The index was created because existing indexes no longer accurately reflected modern market activity for traders and investors.
• Originally called the SE-100, it was renamed FT-SE 100 after the Financial Times joined as a partner, later shortened to FTSE 100.
• Its launch underpinned a new LIFFE futures contract introduced months later in May 1984, expanding its financial market utility.

What Is the FTSE 100 and What Does It Measure?

The FTSE 100, commonly known as the "Footsie," tracks the 100 most highly capitalised blue-chip companies listed on the London Stock Exchange, measuring their performance based on market capitalisation rather than dividend income. It's the UK's best-known stock market index and serves as the primary benchmark for judging the health of British equities.

You'll find the index captures significant market breadth, spanning banking, retail, insurance, industrials, and consumer goods. Larger companies carry heavier sector weights, meaning their price movements influence the index more than smaller constituents. Investors and traders use it to manage portfolios, track risk, and gauge broader UK economic sentiment. It's also frequently featured in media reports, making it a visible and widely recognised financial indicator. Much like a brand archetype concept, the FTSE 100 functions as an anchor — a culturally embedded symbol that simplifies how the public identifies and interprets the health of the broader market.

Why the FTSE 100 Was Created in 1984

Understanding what the FTSE 100 measures only tells part of the story — knowing why it was built explains the gap it was designed to fill.

By 1984, the UK's market structure had outgrown its existing indexes. Earlier benchmarks didn't reflect market activity accurately enough for modern needs, leaving traders and investors without reliable trader tools to manage portfolios and control risk effectively.

The London Stock Exchange created the FTSE 100 to solve that problem directly. Set at a base level of 1,000 points, it tracked the 100 most highly capitalised companies on the exchange, giving you a cleaner, more responsive snapshot of market performance.

It also served a practical purpose from day one — underpinning the new LIFFE futures contract, which launched just months later in May 1984.

How Did the FTSE 100 Get Its Name?

Before it carried the name most people recognise today, the index started out as something far simpler — the SE-100. That name origin reflected its connection to the London Stock Exchange, but it wouldn't stick for long.

When the Financial Times joined as an index partner, the branding evolution began. The name changed to FT-SE 100, combining both organisations' identities into something more recognisable. Over time, that hyphenated version shortened further into FTSE 100 — the name you'll hear on every financial news broadcast today.

Most people also call it the FTSE or "Footsie," a nickname that reflects how embedded it's become in everyday conversation. What started as a functional label transformed into one of the most recognised financial brand names in the world.

How the FTSE 100 Is Calculated and Weighted

Market capitalisation sits at the heart of how the FTSE 100 works. Each company's weight in the index reflects its free float market cap — the shares actually available for public trading, not the total issued. Larger companies move the index more than smaller ones.

• Market cap determines which 100 companies qualify and how much influence each carries
• Free float excludes shares held by insiders or governments, giving you a truer picture of tradeable value
• Index rebalancing happens quarterly, when the London Stock Exchange reviews membership and adjusts weightings

Sector caps don't apply to the FTSE 100, meaning a single sector can dominate if its companies grow large enough. Understanding this weighting structure helps you interpret what index movements actually signal about market conditions.

The Original 100 Companies in the 1984 FTSE 100

When the FTSE 100 launched on 3 January 1984, it drew its founding membership from the largest 100 UK companies by market capitalisation. You'll find the sector breakdown covered banking, retail, insurance, industrials, and consumer goods. Familiar names like Barclays, Lloyds, Tesco, Sainsbury's, and Unilever held founding spots.

Studying their board composition reveals experienced leadership teams that had navigated post-war economic shifts and early globalisation. Many members carried rich IPO histories stretching back decades, reflecting Britain's deep capital markets tradition.

Merger patterns also shaped the list, as consolidation across banking and industrials had already concentrated market value among fewer, larger firms. Over the following decades, only 26 of those original 100 companies survived to feature in the index's 40th-anniversary membership. Much like the Marylebone Cricket Club, which codified the Laws of Cricket in 1788 to bring formal structure to a growing institution, the FTSE 100 launch represented a defining moment of standardisation for British financial markets.

Which Original 1984 Companies Still Survive Today?

Of those original 100 companies, only 26 have held on long enough to appear in the FTSE 100's 40th-anniversary membership — a figure that underscores just how much the UK corporate landscape has shifted since 1984.

These survivor corporate culture shifts reveal how adaptability, not size, determines longevity. Legacy shareholder returns from names like Barclays, Unilever, and Tesco demonstrate that consistent reinvention drives lasting market presence. Exploring tools like category-based fact finders can help contextualize how financial and political events shaped the corporate decisions that determined which companies survived.

What these survivors tell you:

• Adaptability wins — companies that restructured their business models outlasted those that didn't
• Sector shifts matter — banking, retail, and consumer goods dominated early but faced serious consolidation pressure
• Long-term value compounds — staying indexed for four decades delivered measurable, sustained returns to patient shareholders

How Has the FTSE 100 Performed Over 40 Years?

From a base of 1,000 points in January 1984, the FTSE 100 has climbed 654% over four decades — a performance that rewards patient, long-term investors far more than short-term traders chasing quick gains.

If you'd held through periods of long term volatility — crashes, recessions, and geopolitical shocks — you'd have seen the index recover and push higher each time.