The Cash Trap

The maths is not complicated. A £10,000 lump sum placed in a global equity tracker fund in 2004 and left untouched would be worth around £67,000 today, using a 10% annualised return assumption based on long-run developed-market equity history. The same sum in a FTSE 100 tracker, which has underperformed global markets, would still have reached roughly £34,000 after 20 years of dividends reinvested. In cash savings, earning an average of around 1.5% annually (a generous assumption, given that the Bank of England base rate sat at 0.5% or below for the entire decade between 2009 and 2019) the same £10,000 would be worth approximately £13,500.

The gap between the conservative equity outcome (FTSE 100) and cash is £20,500. Between a global tracker and cash, it is £53,500. No single government publication quantifies the aggregate wealth lost by British households holding cash instead of equities over this period, but the arithmetic at the individual level is not in dispute. The question is why so few people act on it.

The FCA's Financial Lives Survey 2024, covering nearly 18,000 UK adults, found that 35% hold some form of investment (shares, funds or investment ISAs). In the United States, Gallup's 2024 polling puts equity ownership at 62%, a figure consistent with three consecutive years of readings. These survey definitions are not identical: Gallup includes stocks held through retirement accounts, while the FCA measures a somewhat different basket of investment holdings. But both point in the same direction. The 27-point gap is unlikely to be explained by income differences alone; it reflects a different relationship with financial markets, built over decades, and a different infrastructure for getting ordinary people into them.

The UK's own history points to what is possible. In the early 1980s, the privatisation of British Telecom, British Gas and other state utilities was accompanied by aggressive public share-offer campaigns. By the early 1990s, around a third of UK adults held shares directly. That figure has since fallen to roughly 18%, according to ShareSoc, as the one-off privatisation cohort aged out and no comparable mechanism replaced it. The investment ISA was introduced in 1999. Twenty-five years later, cash ISAs remain far more widely used: subscriptions run at more than two to one against stocks and shares ISAs.

HMRC's ISA statistics for 2023/24 record total adult ISA subscriptions of approximately £101 billion. Of that, £69.5 billion went into cash ISAs and £31 billion into stocks and shares ISAs. The cash share, 66%, rose sharply in 2022/23 as interest rates climbed from near zero to above 5% for the first time in fifteen years. The relative attractiveness of cash savings at 5% versus the long run is a real phenomenon: for money needed within two to three years, cash is appropriate. The problem is that the behavioural habits formed during a rate spike tend to persist after it ends. As rates fall back toward 3-4%, the case for cash over a five- to ten-year horizon weakens considerably, and most savers do not reassess. None of this means all cash holdings are irrational: emergency liquidity and short-term spending needs are real. The point is that a large share of ISA money appears to be parked in cash on long horizons where the historical equity premium is substantial.

The total stock of ISA wealth tells a different story from the annual subscription data. Of the £725.9 billion held in ISAs at the end of 2022/23, 59% sits in stocks and shares ISAs and 40% in cash, reflecting decades of equity compounding on money that was invested early. The savers who got into equities in the 1990s and 2000s are now sitting on the bulk of ISA wealth. Those who defaulted to cash in the years since are sitting on the smaller pile.

MoneySavingExpert was sold to what is now MONY Group in 2012 for up to £87 million. The group reported £439.2 million in revenue in 2024. The commercial engine is referral fees: MSE earns a commission when a reader clicks through and takes a financial product: a credit card, a savings account, a current account switch, an energy tariff. Products that generate repeat traffic and repeat switching behaviour are worth more to the model than products people set up once and leave alone. A cash ISA best-buy table, updated weekly as rates move, brings readers back regularly. A guide to opening a global tracker ISA does not.

MSE is transparent about its funding model. The site publishes a dedicated disclosure page explaining the asterisk system used to mark affiliate links, and Martin Lewis has publicly called for better investment education and a "starter investment ISA" to push younger savers toward equities. The S&S ISA guide exists and does say, correctly, that for money held five years or more, equities will "usually substantially outperform savings." The editorial case is made. But the commercial weight of a £439 million revenue group sits on products people check weekly, not the Vanguard tracker they would set up in twenty minutes and not touch for a decade. The guide is there; it is not what people come back for.

MSE is not uniquely responsible for this. The broader UK financial media landscape (comparison sites, price aggregators, consumer finance journalism) generates revenue from high-churn products. Long-term investing, by definition, does not churn. The structural incentive is not to suppress the investment case but simply to spend less time and editorial resource on it than its long-run importance warrants.

The FCA estimates that 23 million UK consumers are currently underserved by the financial advice and guidance market. Regulated financial advice (the kind that can legally tell a specific person to open a specific investment product) typically costs £150 to £350 per hour, putting it beyond the majority of savers making routine ISA decisions. Without it, people default to what they know, what their parents did, and what the most-visited financial website recommends most prominently. For most people, that is cash.

Fewer than one in ten UK adults currently obtains regulated financial advice. The FCA and Treasury launched a joint review of the advice guidance boundary in December 2023, with updated rules in 2025 allowing firms to offer "targeted support" in pensions and investments without crossing into full regulated advice. The intention is to allow financial firms to nudge savers toward appropriate long-term products without the liability that comes with personalised regulated advice. Whether this shifts the dial on the 66% cash ISA subscription rate is yet to be seen.

The United States built a different system. The 401(k) and IRA architecture, combined with automatic enrolment defaults that place contributions into target-date equity funds rather than cash, means that millions of Americans accumulate equity exposure as a condition of employment rather than as a deliberate financial decision. The UK's auto-enrolment regime does something similar for workplace pensions, but the ISA (the primary tax-free savings vehicle outside of pensions) still requires an active decision to go near the stock market. Most people do not make it.