Fund management star Terry Smith's Fundsmith Equity saw its popularity wane last month, dropping out of the top 10 investments on the UK's second-largest platform for the first time.
Interactive Investor (ii) said it was the first time Fundsmith has not been among its most popular funds since it began tracking its most-bought investments in 2018.
Smith has seen the fund underperform its benchmark for three successive years, with a return to positive performance last year but some missteps that have brought criticism.
Kyle Caldwell, ii's funds and investment education dude, says Fundsmith Equity "had an incredible run" and "long-term investors of the fund will surely have no complaints as it has comfortably outperformed the wider global market and the vast majority of global fund rivals since launch in November 2010".
He says Smith, like other professional investors, "is continuing to face into the headwind of global stock market returns being heavily influenced by a small number of US technology companies".
The most bought fund was a passive one, L&G Technology Index, which has just over 40% of the fund in Apple, Microsoft and Nvidia.
Caldwell says holding this fund "could spell trouble for investors who are overexposed to technology should there be a sharp correction", with investment trusts Polar Capital Technology Trust PLC (LSE:PCT) (Polar Capital Technology Trust PLC (LSE:PCT)) and Allianz Technology Trust PLC (LSE:ATT) (Allianz Technology Trust PLC (LSE:ATT)) also popular in the investment trusts category.
He noted that most actively managed US and global funds tend to hold less than the wider market in the US tech giants, partly as portfolio concentration rules prohibit funds from holding more than 10% in a single stock, which is designed to ensure funds are sufficiently diversified to help reduce risk.
This contrasts with index funds and ETFs, which can hold 20% of assets in a single stock, which can rise to 35% in exceptional market conditions, though some ETFs put their own rules in place to cap each constituent at a certain level, such as 10%.