Abrdn has struck a £1.5bn deal to buy the online investment platform Interactive Investor, as the fund manager pushes into the increasingly popular realm of web-based trading. Abrdn, which was known as Standard Life Aberdeen until a vowel-averse name change earlier this year, said it was acquiring a fast-growing business that added 46,000 customers last year, excluding acquisitions, taking the total above 400,000. The business was purchased from the majority shareholder, JC Flowers, a US private equity firm, which controlled Interactive Investor via a holding company, Antler Holdco, registered in Guernsey. The move heralds a significant expansion by Abrdn into direct investment. Firms such as Interactive Investor and its rival Hargreaves Lansdown allow individual “retail” investors the opportunity to exercise control, rather than handing over responsibility to a fund manager. They have become increasingly popular thanks in part to the development of apps and web-based platforms that make trading easier, fuelling increased interest in dealing in financial instruments. While apps such as Robinhood and eToro have targeted small-time “day traders”, often seeking a quick profit on sometimes controversial assets such as cryptocurrency, Interactive Investor has pitched itself at a different clientele. Day trading platforms typically charge no subscription fee, taking a cut of trades and charging withdrawal fees instead. Interactive Investor’s entry-level product requires a subscription of £9.99 per month, with customers able to set up automatic investment plans for free but charged if they make more than one trade per month. Its client base skews older and wealthier, with customers more likely to be prepared to invest for longer-term returns. The average customer is a 57-year-old with £137,454 deposited with the company, significantly more than both day traders and the £82,000 average at Hargreaves Lansdown and AJ Bell. Richard Wilson, the chief executive of Interactive Investor, will continue to lead the business, whose £55bn of assets under administration will increase Abrdn’s direct investment business fivefold, to £69bn. Wilson is expected to report directly to the Abrdn chief executive, Stephen Bird, who has made expansion into retail investing a priority for the Edinburgh-based firm, better known for traditional asset management on behalf of clients. Bird said the deal was a “unique opportunity and a transformative step in delivering our growth strategy”. Interactive Investor was founded in 1994 by the entrepreneur Sherry Coutu, who ran the business until it floated on the London Stock Exchange in 2000. She left after it was bought the following year by Australia’s AMP, which briefly rebranded the business, folding it into its own Ample brand. The chief executive, Tomas Carruthers, led a buyout in 2003, leading to majority ownership by the US private equity firm JC Flowers.