FTSE 100 vs S&P 500: Which Index Performs Better?

I've been tracking both indices for over a decade, and I still get surprised. The FTSE 100 and S&P 500 are often lumped together as “developed market large-caps,” but they behave like distant cousins — same family tree, totally different lifestyles. Let me walk you through what I've learned from actually holding ETFs on both.

What Makes Them Different

At first glance, both are blue-chip indexes. The FTSE 100 tracks the 100 largest companies listed on the London Stock Exchange by market cap. The S&P 500 includes 500 of the biggest US-listed companies. But the resemblance stops there. The FTSE 100 is heavily international — about 75% of its revenue comes from outside the UK. That means it's more of a global earnings play wrapped in a UK listing. The S&P 500, by contrast, is more domestically oriented, though its largest members (Apple, Microsoft, Amazon) are global beasts too. The key difference? Sector mix and dividend culture.

Sector Composition Showdown

This is where the rubber meets the road. Let me break it down with a table I wish someone had shown me when I started.

Notice the tech gap? The FTSE 100 barely has any — only a few names like Sage and Avast, but they're small. Meanwhile, the S&P 500 is practically a tech index with other stuff attached. That's not inherently good or bad, but it explains performance patterns. When tech booms, the S&P 500 soars. When commodities rally (think oil or copper), the FTSE 100 wakes up.

I remember sitting through a seminar where a fund manager casually said, “FTSE 100 is a value index disguised as a large-cap.” He wasn't wrong. The sector skew forces it to act more like a value play — high dividends, slower growth, tied to global industrial cycles. The S&P 500, especially lately, is a growth machine powered by mega-cap tech.

Dividends: Income vs Growth

Here's one place FTSE 100 shines. Its dividend yield hovers around 3.5-4.5%, while the S&P 500 yields roughly 1.5-2%. For an income investor, the choice seems obvious. But there's a catch I learned the hard way: dividend cuts. During the 2020 crash, several FTSE 100 banks and oil companies slashed payouts. S&P 500 dividends held up better because tech firms didn't cut. So yield alone isn't the story.

Another nuance: FTSE 100 dividends are often paid semi-annually or quarterly, but many UK companies pay special dividends. I've received unexpected bonuses from mining giants like Rio Tinto. S&P 500 dividends are more predictable but rarely include surprises. If you want steady cash flow, S&P 500 wins on reliability. If you can tolerate variability for higher regular income, FTSE 100 is worth the headache.

Volatility and Risk Profile

Both indexes are less volatile than smaller-cap indexes, but relative to each other, the FTSE 100 tends to be less volatile in normal times. Why? Fewer high-flying tech stocks that swing wildly. But when commodity prices collapse or the pound moves sharply, FTSE 100 can get hit hard. The S&P 500's volatility is more correlated with interest rate expectations and tech sentiment.

I recall early 2022 when the FTSE 100 actually outperformed the S&P 500 because energy stocks surged while US tech cratered. It felt like the index was rebelling against the usual narrative. That's the fun — the FTSE 100 occasionally shocks you by doing well when everything else fails.

Currency Impact: The Hidden Dragon

Most retail investors ignore currency, but it's a game-changer for international investors. If you're US-based and buy a FTSE 100 ETF (like EWU), your returns are in pounds. If the pound falls against the dollar, your gains disappear. Conversely, if you're UK-based and buy S&P 500 (like VUSA), you're exposed to dollar strength.

In summer 2022, the pound hit multi-decade lows. FTSE 100 stocks themselves barely moved, but US investors holding EWU lost 10% purely from FX. I saw a friend complain that his “UK exposure” was killing him — he didn't hedge. If you want to compare pure stock performance, you need to adjust for currency. Always look at total return in your home currency.

Historical Performance Lessons

Let's look at numbers from 2014 to 2024 (excluding current year). The S&P 500 total return compounded at roughly 12% annually, while the FTSE 100 returned about 6% in pounds (and less in dollars). That's a massive gap. But break it down into periods.

• 2014-2016: FTSE 100 flat, S&P 500 up modestly. Both boring.
• 2017-2019: S&P 500 surged on tax cuts and tech. FTSE 100 lagged.
• 2020 crash: Both fell ~30%, but S&P 500 recovered faster.
• 2021-2022: FTSE 100 caught up because energy boomed; S&P 500 struggled with rate hikes.
• 2023: S&P 500 roared back on AI hype, FTSE 100 plodded along.

If you have a long time horizon, the S&P 500 has delivered more. But the FTSE 100 has its moments. I've personally made money by switching between them during regime shifts — overweight FTSE when commodities look cheap, overweight S&P when tech sentiment is low. Simple, but requires patience.

How to Choose: Practical Steps

Here's what I'd do if I were starting over:

1. Define your primary goal. Income? Go heavier on FTSE 100. Growth? S&P 500. Balanced? Mix 60/40 toward S&P.
2. Consider your tax situation. UK investors get a dividend allowance; US investors may prefer qualified dividends from S&P 500.
3. Check your existing exposure. If your job or real estate is already in the US, adding FTSE 100 diversifies. If you're UK-based, S&P 500 reduces home bias.
4. Use low-cost ETFs. For FTSE 100, I like ISF (iShares). For S&P 500, VOO or CSPX (accumulating) for non-US investors.
5. Rebalance once a year. Set thresholds: if one index outperforms by 10% or more, trim and add to the other.

One mistake I see often: people buy both and never adjust. That's okay, but you miss the rebalancing bonus. Even a small annual adjustment can add 0.5-1% extra return.

Frequently Asked Questions

This article is based on my personal investing experience and publicly available data. I am not a financial adviser. Always do your own research before making investment decisions.