Diamond Hill Mid Cap Strategy’s Q4 2025 Investor Letter

Diamond Hill Capital, an investment management company, released its “Mid Strategy” fourth-quarter 2025 investor letter. The fourth quarter posted another period of favorable gains for equity markets, with small and large cap positions being stronger performers, returning 2.19% and 2.41%. While the mid-cap range was a relative laggard, with the Russell Mid Cap Index returning 0.16%. The Strategy returned 3.65% (net) in Q4, compared to 0.16% return for the Russell Midcap Index. YTD, the strategy returned 13.47% (net), outperforming the 10.60% return for the Index. In 2025, AI-related spending remained a key driver in equity markets, though December saw a pause as investors became more cautious about AI developments and potential market bubbles. Given the elevated valuation in the equity market, the Strategy is well-positioned for ongoing levels of heightened uncertainty going forward. Please review the Strategy’s top five holdings to gain insights into their key selections for 2025.

A copy of Diamond Hill Mid Cap Strategy’s Q4 2025 investor letter can be downloaded here.