Dedicated US funds and technology funds, which tend to be around 85% invested in the US, dominated the list of funds bought by HL SIPP and SIPP drawdown investors.

Victoria Hasler, head of fund research, Hargreaves Lansdown, said: “The US market has performed well over the year to date, with the S&P 500 returning 11.4% in sterling terms over the five months to the end of May. That compares to a return from the FTSE All Share index of 8.7%.”

She said technology stocks also had a good run, “although performance between the so-called ‘Magnificent 7’ is now starting to diverge.”

She said the markets could all offer good long term growth potential, but investors may want to consider how much total exposure they have to US, and in particular to technology, stocks given the large overlap between the technology, US and global markets.

The figures showed that Jupiter India remained in the top five most popular funds for both SIPP and SIPP drawdown investors. Meanwhile passive funds also remained popular.

Ms Hasler said: “Passive funds were the go-to choice for both HL SIPP and SIPP drawdown investors, with just three active funds appearing in their top ten list. These were Jupiter India, Fundsmith Equity and Rathbone Global Opportunities.

The trend towards passive funds is no surprise, but rather a continuation of something we have been seeing for many years now. These funds have low fees and offer an easy way to access markets such as the US and global equities.”

 Ms Hasler noted that both lists were dominated by equity funds, with no bond funds or other asset classes on the list.

She said: “This is unsurprising given how strong equity markets have been of late, and of course we don’t know what the investors buying these funds already hold in their portfolios, but it has certainly been some time since fixed income has been in vogue with retail investors. With bond yields so high, however, this could be a mistake – now is an attractive time to add some diversification to a portfolio and gain some welcome income – particularly for those in retirement.”