The Wall Street Journal took a data analysis from MDA DataQuick and compared the most common last names in the Bay Area from 1999 and 2009. The 10 most common last names among Bay Area home buyers last year were Vietnamese, Chinese or Korean, up from five of 10 in 1999.

Li, Wang, Liu, Huang and Chan knocked Smith, Johnson, Garcia, Williams and Miller out of the top 10 over the  last decade. The data was in correlation with trends tracked by the Census Bureau, which found that roughly 19% of homeowners in the San Francisco-San Jose-Oakland region in 2008 were Asian, up from about 15% in 2000. The data exclude mixed-ethnicity households.
Top 10 most popular last names of home buyers in 2009:
1. Nguyen
2. Chen
3. Lee
4. Wong
5. Li
6. Wang
7. Tran
8. Liu
9. Huang
10. Chan
 Source - Carrie Tuna WSJ