In 40 years, Bill Tanner and Peter Mainstain have seen a lot of changes in the real estate market. Prices skyrocketed in the ‘70s — particularly in Southern California — and continued to rise over the decades. While there have been cycles of boom and bust, real estate’s long-term upward trajectory has been more than healthy enough to make it the cornerstone of the firm’s investment strategy.

“We haven’t missed a year of investing in real estate, not only in Los Angeles, but throughout the United States,” says Tanner. “With specific general partners that Peter and I invest with first, we test the market, how they report and all the variables, and, once it comes back to us that they’re successful in their endeavor with us, we bring in our clients to invest as well. We’re limited partners in everything we do, meaning we have no liability.”

At first, they focused on apartments and storage facilities, then branched out into small shopping centers that would generally include a supermarket, a liquor store, and several other small businesses such as nail salons.

“The typical shopping center we invested in was 100,000 to 150,000 square feet,” says Mainstain. “That sounds like a lot, but it’s a lot different than your typical Westfield mall. Those are 500,000 to a million square feet.”

Over the years, Tanner Mainstain’s shopping center investments have trended smaller, as tenants have shifted from retail stores like Best Buy and the now-defunct Circuit City to service businesses such as restaurants and gyms.

“Even the retailers that have stayed in business don’t use as much space as they used to,” observes Mainstain. “They’re carrying less inventory and trying to have a duplicate strategy, both on the internet and in a retail space.”

These days, Tanner Mainstain’s real estate investments are increasingly focusing on assisted-living facilities, which are rising in demand as the baby boomers age, and apartment buildings outside Southern California. “It’s hard to find ones that make sense financially in L.A.,” Mainstain says.

According to the duo, current real-estate investment hot spots include growing tech hub Portland, Ore., and Reno, where electric car manufacturer Tesla is building a $5 billion battery factory.

The population for the Reno-Sparks metropolitan area is 400,000, “and they’re expecting it to go to 600,000 within four years,” says Mainstain. “That’s a huge increase. They have to live somewhere, buy groceries, go out to restaurants.”