The H Mart of today is a $2 billion company with 96 stores and a namesake book (the best-selling memoir “Crying in H Mart,” by the musician Michelle Zauner). Last month, the chain purchased an entire shopping center in San Francisco for $37 million. Patel Brothers has 52 locations in 20 states, with six more stores planned in the next two years. 99 Ranch opened four new branches just last year, bringing its reach to 62 stores in 11 states. Weee!, an online Asian food store, is valued at $4.1 billion.