When a Lisbon investment fund paid 48 million pounds this month for a 60 percent stake in a women’s club in the north of England, the headline number was the one that drew attention. The club finished sixth last season, plays in a 5,000-seat ground it shares with a nonleague men’s team, and lost 3.1 million pounds. Three years ago, a similar stake in a comparable club changed hands for about 7 million pounds.

The deal, confirmed on Thursday by the fund, Tagus Sports Capital, is the sixth majority sale of a top-flight women’s club in Europe this year and the largest. It follows purchases in France, Spain and Germany by American private equity groups, a Gulf-backed holding company and, in one case, a group of former players. By the count of the consultancy Pitchside Advisory, 1.1 billion euros of capital has gone into European women’s clubs since the start of 2024, against about 180 million in the three years before.

“The thesis is simple, which is why so many people share it,” said Inês Saraiva, the managing partner of Tagus, in an interview in London on Friday. “Audiences are growing faster than in any other sport in Europe. Media rights are underpriced because the contracts were signed before the growth. And the clubs are cheap because for 50 years nobody thought they were worth anything.”

The numbers support the first two points. Attendance in England’s top women’s league rose 22 percent last season to an average of 7,800, and the league’s domestic broadcast deal, which runs to 2029, is worth about 65 million pounds over five years, a figure that analysts expect to at least double at renewal. Spain’s league drew a record 2.9 million viewers for its final in May.

Whether the clubs are cheap is the harder question. Almost none make money. The English league’s 12 clubs lost a combined 41 million pounds last season, according to filings, and those with the largest crowds are still overwhelmingly the women’s sides of big men’s clubs, which absorb losses as a brand expense. Independent clubs, the kind investors are buying, have the growth but not the cushion.

“What is being bought is an option on a media deal that has not been signed yet,” said Dr. Helen Okonjo-Carr, who studies sports finance at Loughborough University. “If the renewal comes in at three times the current figure, the buyers look clever. If the leagues cannot agree on a format, or the men’s clubs decide they want the money, the independents are the first to feel it.”

The wave has also raised questions about ownership rules. Several countries bar the same investor from holding stakes in two clubs in the same competition, and leagues have had to decide whether a fund that owns a women’s club and a stake in a different men’s club is in conflict. England’s league introduced a fit-and-proper owner test for women’s clubs only in 2025.

Ms. Saraiva said Tagus planned to move the club into a 12,000-seat stadium by 2028 and had budgeted for losses until then. “Everyone who bought a men’s club in 1995 looks like a genius now,” she said. “Nobody remembers that in 1995 they looked like a fool.”