As a UK investor, you have access to thousands of stocks across dozens of international markets through a standard Stocks & Shares ISA or SIPP. But two markets dominate most private investor portfolios and conversations: the FTSE 100 — the benchmark index of the London Stock Exchange — and the NASDAQ — the US technology-heavy exchange that has been the engine of global equity returns for the past three decades.
Understanding the fundamental differences between these two markets — not just in terms of past performance, but in terms of composition, risk profile, dividend characteristics, currency exposure, and tax treatment — is essential for making informed allocation decisions. This guide gives you the full picture.
The FTSE 100 is an index comprising the 100 companies with the largest market capitalisation listed on the London Stock Exchange. It was established in January 1984 with a base level of 1,000 points and has become the defining benchmark for UK equity markets globally.
What many investors — including some with years of experience — fail to appreciate is that the FTSE 100 is not a UK economy index in any meaningful sense. The companies that comprise it are listed in London, but the vast majority of their revenues, profits and operations are global. Shell and BP generate revenues across every continent. HSBC earns the majority of its profits in Asia. Rio Tinto mines in Australia, Mongolia, Canada and Guinea. Unilever sells consumer goods in 190 countries. AstraZeneca's pharmaceutical revenues are global.
Approximately 75–80% of FTSE 100 revenues come from outside the United Kingdom. This has a crucial implication: when the UK economy performs poorly, it does not necessarily translate into poor FTSE 100 performance. The index is effectively a collection of globally diversified multinationals that happen to be headquartered in or listed from London.
| Sector | Weight | Key Companies |
|---|---|---|
| Financials | ~20% | HSBC, Lloyds, Barclays, Standard Chartered, Legal & General |
| Energy | ~14% | Shell, BP |
| Consumer Staples | ~12% | Unilever, Diageo, Reckitt |
| Healthcare | ~12% | AstraZeneca, GSK |
| Mining / Materials | ~10% | Rio Tinto, BHP, Glencore, Anglo American |
| Industrials | ~10% | BAE Systems, Rolls-Royce, Smiths Group |
| Technology / Data | ~7% | RELX, Sage, Experian |
| Other | ~15% | Utilities, Telecoms, Real Estate, Retail |
Notice what is largely absent: pure-play consumer technology companies. The FTSE 100 contains no company comparable to Apple, Microsoft, Amazon, Google, or Meta. This is the most significant structural difference between the FTSE 100 and NASDAQ, and it largely explains their divergent long-term performance records.
Average dividend yield of FTSE 100: approximately 3.5–4.0%, making it one of the higher-yielding major indices globally. This reflects the mature, cash-generative nature of many of its largest constituents.
NASDAQ (National Association of Securities Dealers Automated Quotations) was founded in 1971 as the world's first electronic stock exchange. Originally seen as a home for smaller, speculative growth companies, it transformed over the following decades into the exchange where the world's most valuable and innovative technology businesses chose to list.
The most widely followed NASDAQ index is the NASDAQ-100, which tracks the 100 largest non-financial companies listed on the NASDAQ exchange. Its composition is strikingly concentrated compared to the diversified FTSE 100:
The largest five companies in the NASDAQ-100 — Apple, Microsoft, NVIDIA, Amazon and Alphabet — together often represent 40–45% of the entire index. This is extraordinary concentration in a small number of companies, and it means the NASDAQ-100's performance is heavily driven by the fortunes of a very small group of businesses.
Average dividend yield of NASDAQ-100: below 1%. NASDAQ companies — particularly the large technology firms — prioritise reinvesting profits into growth or returning cash via share buybacks rather than dividends. Investors in NASDAQ are primarily seeking capital appreciation, not income.
The long-term performance comparison between FTSE 100 and NASDAQ is not close — and UK investors who have been exclusively "home biased" toward FTSE 100 equities over the past two decades have significantly underperformed their peers with broader US and global exposure.
This enormous performance gap is driven almost entirely by the technology sector's dominance of NASDAQ returns — specifically the rise of software, cloud computing, e-commerce, and AI over the past two decades. These structural trends did not exist in the FTSE 100 to anything like the same degree.
However, this comparison requires important caveats.
NASDAQ's higher long-term returns came with dramatically higher short-term volatility and catastrophic drawdowns:
By comparison, the FTSE 100 has been significantly less volatile. Its worst drawdown during the dot-com era was approximately 50% — severe, but considerably less than NASDAQ's 78%. During 2022, the FTSE 100 actually held up relatively well due to its heavy weighting toward energy companies (which benefited from rising oil prices) and financials (which benefited from rising interest rates).
The correct frame is not "which is better" but "what combination suits my risk tolerance, time horizon, and investment goals?"
When a UK investor buys US stocks through a Stocks & Shares ISA or SIPP, they are implicitly taking a position on the GBP/USD exchange rate. Here is why this matters.
If you buy Apple shares at a price of $180 when the exchange rate is £1 = $1.27, you are effectively paying approximately £142 per share. If Apple's share price rises 15% to $207, but the pound has also strengthened to £1 = $1.46, your return in sterling terms is approximately 0%. The share price gain has been entirely cancelled out by currency movement.
Conversely, if the pound weakens — as it did sharply after the Brexit referendum in 2016 and again during the 2022 mini-budget crisis — UK investors in US stocks benefit, because their dollar-denominated holdings are worth more in sterling terms even if the dollar price hasn't moved.
Currency risk adds approximately 5–10% annualised volatility to UK investors' US equity exposure on top of the underlying stock market volatility. Over long periods, GBP/USD tends to oscillate within ranges, meaning currency effects often partially cancel out. But they can be significant over shorter periods and should be factored into your thinking.
Some ISA providers offer currency-hedged ETFs (for example, an S&P 500 ETF hedged to GBP) that remove this currency exposure. These are worth considering for investors who want US equity returns without the currency noise, though they carry a small additional cost.
Despite the long-term return gap, there are genuine and compelling reasons for UK investors to maintain meaningful FTSE 100 exposure:
Both FTSE 100 and US stocks are available within a Stocks & Shares ISA, meaning capital gains and UK income tax on dividends are sheltered regardless of which market you invest in.
However, US stocks have a specific tax complication: US withholding tax on dividends. The US government withholds 30% of dividends paid to non-US investors by default. Under the UK-US tax treaty, this is reduced to 15% for UK investors — but only if you have completed a W-8BEN form with your broker, which declares your UK tax residency. Most UK brokers (Hargreaves Lansdown, AJ Bell, Freetrade) handle this automatically for ISA accounts. Check your broker's policy.
This 15% withholding tax cannot be reclaimed within an ISA (unlike in a general investment account where foreign withholding tax can sometimes be credited against UK income tax). This is why US dividend-paying stocks may be marginally better held in a SIPP than an ISA for higher-rate taxpayers — in a SIPP, the effective tax rate on future drawdowns may be lower than the 15% upfront cost.
Most professional UK fund managers — including those running diversified "growth" or "balanced" funds for pension schemes and retail investors — hold both. A typical allocation for a UK-domiciled globally diversified equity portfolio might look something like:
The exact split depends on risk tolerance, time horizon, income requirements and personal conviction. But the principle is clear: neither market is "right" and neither should be the whole story. The FTSE 100 and NASDAQ complement each other in a well-constructed portfolio, providing sector diversification, geographic diversification, and income/growth balance.
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