Depending on the neighborhood, foreign (mostly People’s Republic of China) purchases can range up to 3/4 of purchases, per some of the leading realtors. (And yes, the realtors are marketing in China, including advertising and direct sales in Shanghai, Beijing hotels/ meeting halls. One realtor at least has purchased a small airplane to take visiting buyers on air tours over the houses on sale, that one and others provide Chinese with direct San Francisco airport pickup and van sales tours complete with purchase bid/contract packages so that sales can be completed in the vans on the way back to dropping the buyers off to catch their return flights to Asia.)
My lawyer considered learning Chinese because there were so many buyers from China. All cash. All over asking.