Last year was tough for investors, as war in Ukraine, rocketing inflation, rising interest rates and Chinese lockdowns hit global stock markets.

US technology shares were hit hardest of all, as companies such as Meta (formerly Facebook), Netflix and Tesla crashed after becoming overvalued during the boom.

Some of the most successful investment funds of the last decade were focused on US stocks, and suffered in the sell-off.

One of them was Fundsmith Equity, the most popular and successful UK-listed investment fund of all, massively popular among Isa investors.

It was launched in November 2010 by Terry Smith, who has defied his humdrum name to become the undisputed star of the fund management world.

Ordinary Isa investors flocked to buy his flagship fund, which now manages a staggering £24.5billion.

Yet last year, there were rumblings that Smith's incredible run of success was coming to an end as Fundsmith Equity lost billions.

Its value crashed by 13.8 percent last year, performing far worse than its benchmark index MSCI World, which fell a relatively small 7.8 percent.

Investors in Fundsmith had got used to beating the market, so this came as a shock.

In his annual letter to shareholders, Smith admitted he'd done poorly saying that periods of underperformance are never welcome but “nonetheless inevitable”.

Yet he has nothing to apologise for today, as his fund is fighting back strongly.

Over the last six months, Fundsmith Equity has delivered a total return of 10.2 percent, according to figures from Trustnet.

By comparison, the average fund in his sector climbed just four percent. Smith’s longer-term performance is even more impressive.

Between launch in November 2010 and the end of last month, a period of roughly twelve-and-a-half years, Fundsmith Equity delivered a staggering total return of 518 percent, with dividends reinvested. 

That would have turned a £10,000 investment at launch into a hugely impressive £61,800. No wonder most investors stuck with him despite last year's troubles.

Smith has thrashed his benchmark index over the longer run. MSCI World delivered a total return of 273.9 percent over the same period, turning £10,000 into £37,390. 

That's a good return but is still £24,410 less than Fundsmith Equity.

Every UK adult got a new Isa allowance from 6 April, allowing them to invest up to £20,000 a year in either cash or stocks and shares, free of tax.

Million still prefer cash, because it is low risk, but the returns are lower too.

Somebody who had put £10,000 into the average cash deposit account in November 2010 would have seen a total return of just 8.8 percent. They would have £10,880 today.

Cash Isa rates have picked up lately, but even an average return of four percent a year over twelve-and-a-half years would only turn £10,000 into £16,327.

That’s a fraction of what Smith has delivered.

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Every saver needs some cash in the bank where it can be accessed in an emergency, said Victoria Scholar, head of investment at Interactive Investor. "But for long-term savings, the stock market should deliver a much better return."

Terry Smith built his reputation by investing in solid global stocks listed in the US and Europe, such as Microsoft, Novo Nordisk, L'Oreal, cigarette maker Philip Morris, Estée Lauder and Visa.

He has held some tech stocks, including Meta Platforms, PayPal and Amazon, but avoided making too many high-risk bets.

That’s another reason why investors like him.

Yet Fundsmith’s stellar past performance is no guarantee of future success.

Neil Woodford was once the UK’s heavyweight fund manager, but lost his way after setting up on his own.

Loyal investors lost fortunes, after the hugely popular Woodford Equity Income Fund went from being the best to worst in the UK.

There is a danger that success could go to Smith's head, too. He’s now a supremely wealthy man based in Mauritius who made £190million last year, under a complex partnership package that includes a share of the profits.

But as this year’s fightback confirms, no other Isa fund manager can match him today.