Top 10 best-selling ISA and SIPP funds in May

As we approach the middle of 2025, cash is still king for personal investors. ‘Money market’ funds dominated our best-sellers list last month, with the Fidelity Cash Fund proving particularly popular.  

Further down the rankings, however, some interesting changes are afoot. Confidence in the technology sector appears to be recovering after the tariff-induced turmoil, while interest in the biggest UK companies is fading again. Investors are still on the lookout for British bargains though, with a value-focused fund staging an impressive comeback.  

• See our current offers to help make your money go further.
• Get updates on markets, ISA funds, pension saving and much more

The most popular ISA funds in May

The four most popular ISA funds are proving hard to dislodge. The Fidelity Cash Fund retained top position in May, but money continued to flow into the Royal London Short Term Money Market Fund as well. After achieving returns of roughly 5% last year¹, it is easy to see why these low-risk vehicles are thriving, but they could lose their lustre if the Bank of England starts cutting interest rates in earnest.  

For equity hunters, the Fidelity Index World Fund is still the global tracker of choice, while the Fidelity Global Dividend Fund is a favourite for income-seekers.  

Competition is heating up further down the table, however. The Legal & General Cash Trust has been kicked out of fifth position by the more adventurous Fidelity Special Situations Fund, which is enjoying a successful run. The fund focuses on lowly valued UK companies with recovery potential.  

Elsewhere, demand for London-listed stocks has waned. The Fidelity Index UK Fund has dropped out of the best-sellers list and - at the same time - interest in international tech has increased. The Legal & General Global Technology Index Trust has been joined by the Fidelity Global Technology Fund, which counts Taiwan Semiconductors as its biggest holding and has less exposure to the ‘Magnificent 7’ than your typical tech tracker.

The rise of this actively managed fund suggests tech is firmly back in favour - but some investors are clearly looking beyond the big US names, which are highly valued and have been buffeted by Donald Trump’s tariff plans.  

Top 10 best-selling ISA funds on Fidelity Personal Investing in May 2025

1. Fidelity Cash Fund
2. Fidelity Index World Fund
3. Fidelity Global Dividend Fund
4. Royal London Short Term Money Market Fund 
5. Fidelity Special Situations Fund
6. Fidelity Index US Fund 
7. Legal & General Global Technology Index Trust
8. Fidelity Global Technology Fund 
9. Rathbone Global Opportunities Fund 
10. Legal & General Cash Trust 

Source: Fidelity International. Gross ISA sales in May 2025 for Personal Investors only.  

The most popular SIPP funds in May  

SIPP investors are also seeking out steady, cash-like returns, with the Fidelity Cash Fund, Royal London Short Term Money Market Fund, and Legal & General Cash Trust occupying first, third and fourth place respectively.  

A different type of safe haven has fallen out of favour, however: Ninety One Global Gold Fund, which invests in gold miners, made a fleeting appearance in the top 10 in April but left again in May. Gold has experienced a record rally this year, but some investors are now fretting that the price has peaked. 

Another notable exit from the top 10 is the Rathbone Global Opportunities Fund. This active, growth-seeking fund was replaced by the Fidelity Global Aggregate Bond Feeder Fund, which obtains exposure to fixed income securities around the world. This is the first dedicated bond fund to appear in the top 10 this year and suggests SIPP savers are diversifying away from a choppy and unpredictable stock market. 

Top 10 best-selling SIPP funds on Fidelity Personal Investing in May 2025 

1. Fidelity Cash Fund
2. Fidelity Index World Fund
3. Royal London Short Term Money Market Fund
4. Legal & General Cash Trust
5. Fidelity Global Dividend Fund
6. Fidelity Global Aggregate Bond Feeder Fund
7. Fidelity Index US Fund
8. Legal & General Global Technology Index Trust
9. Fidelity Global Technology Fund
10. Fidelity Special Situations Fund

Source: Fidelity International. Gross ISA sales in May 2025 for Personal Investors only. 

¹Royal London Asset Management, 30 April 2025.

Important information - investors should note that the views expressed may no longer be current and may have already been acted upon. Before investing into a fund, please read the relevant key information document which contains important information about the fund. Eligibility to invest in a SIPP or ISA and tax treatment depends on personal circumstances and all tax rules may change in the future. Withdrawals from a SIPP will not normally be possible until you reach age 55 (57 from 2028). Overseas investments will be affected by movements in currency exchange rates. Investments in emerging markets can be more volatile than other more developed markets. Reference to specific securities should not be construed as a recommendation to buy or sell these securities and is included for the purposes of illustration only. There is a risk that the issuers of bonds may not be able to repay the money they have borrowed or make interest payments. When interest rates rise, bonds may fall in value. Rising interest rates may cause the value of your investment to fall. An investment in a money market fund is different from an investment in deposits, as the principal invested in an money market fund is capable of fluctuation. Fidelity’s money market funds do not rely on external support for guaranteeing the liquidity of the money market funds or stabilising the NAV per unit or share. An investment in a money market fund is not guaranteed. This information is not a personal recommendation for any particular investment. If you are unsure about the suitability of an investment you should speak to one of Fidelity’s advisers or an authorised financial adviser of your choice.