Longleaf Partners Small-Cap Fund’s Investment Theses for White Mountains (WTM)

Longleaf Partners, managed by Southeastern Asset Management, released its “Small-Cap Fund” third-quarter 2025 investor letter. A copy of the letter can be downloaded here. The fund returned 2.03% in the third quarter, compared with the Russell 3000’s 8.18% and the Russell 2000’s 12.39%. For more information on the fund’s best picks in 2025, please check its top five holdings.

In its third-quarter 2025 investor letter, Longleaf Partners Small-Cap Fund highlighted stocks such as White Mountains Insurance Group, Ltd. (NYSE:WTM). Headquartered in Hamilton, Bermuda, White Mountains Insurance Group, Ltd. (NYSE:WTM) is an insurance and other financial services provider. The one-month return of White Mountains Insurance Group, Ltd. (NYSE:WTM) was 5.43%, and its shares gained 2.04% of their value over the last 52 weeks. On December 1, 2025, White Mountains Insurance Group, Ltd. (NYSE:WTM) stock closed at $2,024.89 per share, with a market capitalization of $5.17 billion.

Longleaf Partners Small-Cap Fund stated the following regarding White Mountains Insurance Group, Ltd. (NYSE:WTM) in its third quarter 2025 investor letter:

“We were glad to be able to increase our weighting in this insurance holding company at discounted prices during the quarter. White Mountains Insurance Group, Ltd. (NYSE:WTM) remains one of the most value-per-share-focused companies we know. They demonstrated this once again after quarter end with the highly accretive sale of their controlling interest in Bamboo for nearly a 4x return in ~2 years of ownership.”

Is White Mountains Insurance Group, Ltd. (WTM) the Highest-Priced Stock Right Now?

White Mountains Insurance Group, Ltd. (NYSE:WTM) is not on our list of 30 Most Popular Stocks Among Hedge Funds. According to our database, 26 hedge fund portfolios held White Mountains Insurance Group, Ltd. (NYSE:WTM) at the end of the third quarter, up from 20 in the previous quarter. While we acknowledge the risk and potential of White Mountains Insurance Group, Ltd. (NYSE:WTM) as an investment, our conviction lies in the belief that some AI stocks hold greater promise for delivering higher returns and doing so within a shorter time frame. If you are looking for an AI stock that is more promising than White Mountains Insurance Group, Ltd. (NYSE:WTM) and that has 10,000% upside potential, check out our report about this cheapest AI stock.

In another article, we covered White Mountains Insurance Group, Ltd. (NYSE:WTM) and shared The London Company Small Cap Strategy’s views on the company. In addition, please check out our hedge fund investor letters Q3 2025 page for more investor letters from hedge funds and other leading investors.

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Disclosure: None. This article is originally published at Insider Monkey.