Investors own roughly 1 in 6 Southern California houses.

That’s what my trusty spreadsheet found when it reviewed local investor statistics from BatchData, which analyzed who owns 3.8 million single-family houses in Los Angeles, Orange, Riverside, San Bernardino, San Diego and Ventura counties.

The data tracker digs into property records more thoroughly than many traditional real estate analysts. BatchData reviewed ownership records to separate owner-occupied residences from what investors control — including second homes and vacation retreats. This math does not apply condos or build-to-rent single-family home projects.

As of March, BatchData found 637,314 local single-family houses owned by investors, or 17% of the Southern California market. Statewide, 19% of houses are owned by investors. Nationally, it’s 20%.

By county, San Bernardino is No. 1 at 27%, then Riverside at 19%, San Diego and Orange at 16%, Los Angeles at 15% and Ventura at 14%. Why San Bernardino? It has more affordable houses, and its mountains and lakes are recreational draws, both for second homes and rentals.

Do not forget that wannabe homeowners face plenty of competition from investors, who increased their local stakes by 3,923 houses in the first quarter of 2025. That equals a dip in net additions of 1% versus a year earlier.

Sales of all single-family houses, as a comparison, grew 3% in the same 12-month period, according to data from Attom.

The net result comes from investors buying 8,749 houses in the first quarter at a $1.06 million average price while selling 3,923 at essentially the same average price.

Debate swirls about how much the demand from investors adds to affordability woes for house shoppers seeking their own place to live. But if you wonder who’s buying with high prices and mortgage rates, investors remain willing.

Last year, local investors added 15,483 houses to their holdings — buying 35,032 at an average $1.08 million while selling 19,549 at an average of $1.05 million.

Compared to the investment pace from 2020 to 2023, last year represented 23% more net additions, 7% more purchases, and a 3% decline in sales.

Meanwhile, the region’s sales of all single-family houses shrank 25% in the same time frame, Attom says.

Jonathan Lansner is the business columnist for the Southern California News Group. He can be reached at jlansner@scng.com.