The market’s concentration around artificial intelligence (AI) stocks continues to challenge Alliance Witan (ALW). Extending a trend from the previous two years, the £4.9bn FTSE 100 constituent said its diversified multi-manager portfolio underperformed in the first half of the year, returning 7% against the 12.7% total return from the MSCI All Country World index.

Alliance Witan said that with its board’s support, investment adviser WTW was conducting a “structured review” of fund manager selection, stock picking, portfolio construction and risk management. “While no major change is expected to the company’s diversified, high-conviction approach, the review will guide any future enhancements to our…