White Mountains Insurance Group valued its stake in BroadStreet Partners at $176.8 million at Sept. 30, up less than 1% from the prior quarter, according to its quarterly filing with the SEC. The figure shows gains on the brokerage investment slowing.
BroadStreet’s own revenue and earnings are not public, and White Mountains’ third-quarter earnings released Thursday does not discuss the brokerage. The valuation is the clearest read on the investment’s performance available.
White Mountains put $150 million into BroadStreet through a special purpose vehicle on July 18, 2025, as part of an investor group led by Ethos Capital, British Columbia Investment Management Corporation and White Mountains. The carrying value of its interest was $160 million at Dec. 31, 2025, then $170.1 million at March 31, $176.2 million at June 30 and $176.8 million at Sept. 30, according to the company’s filings.
That is a rise of $16.8 million, or 10.5%, over the first nine months of 2026. But the third quarter added only $0.6 million, compared with about $10 million in the first quarter and $6 million in the second. The company values the interest using net asset value and records changes in net realized and unrealized investment gains. It lists the carrying value as its maximum exposure to loss on the interest.
The holding is small for White Mountains. It owns a 10.9% limited partnership interest in the vehicle, equal to less than 5% of BroadStreet on a look-through basis, the company has said. The stake sits within Other Operations, which posted a pre-tax loss of $33 million in the third quarter, largely driven by the decline in MediaAlpha’s share price, the release said.
Based in Columbus, Ohio, BroadStreet is a middle-market brokerage focused on commercial and personal property and casualty insurance and employee benefits. It invests in independent agencies it calls Core Agency Partners. There were 30 as of 2025, with more than 800 professionals holding equity in their local firms, according to BroadStreet’s company profile. The same profile puts combined revenue across those partners at $2 billion or more. Ontario Teachers’ Pension Plan remains a co-control investor, according to White Mountains’ annual investor presentation.
“BroadStreet is well-positioned as the partner of choice for entrepreneurs looking for new growth opportunities,” BroadStreet CEO Mike O’Connor said in April 2025, when the investment was announced. “Our co-ownership model and strategy support our Core Agency Partners as they scale their businesses.”
The valuation offers limited insight into operations. White Mountains did not disclose BroadStreet’s revenue growth, organic growth or acquisition activity, so the data cannot show whether new partners, price changes or valuation multiples drove the change in value.
Agency owners and benefits brokers weighing capital partners may still find the model relevant. Core Agency Partners keep their names and local leadership while gaining access to capital and acquisition support, according to the company profile. A slower quarter for the mark, on its own, says little about how that model is performing for the agencies in it.
