In April 2014, he was appointed the Chairman of Grupo Popular, a company whose subsidiaries include Banco Popular Dominicano, the largest private bank in the Dominican Republic.

Forbes listed Grullón as one of the ten wealthiest men of the Dominican Republic.

[citation needed] His father was the founder of the Banco Popular Dominicano in August 1963, and held the position of President for 25 years.

[5] After completing his education in the United States, obtaining a degree in psychology from Tulane University and a master's degree in business administration from New York University, Grullón returned to his home country, becoming involved in his father's company.

[citation needed] He took over the position of President in 1990 when his father Alejandro Grullón was appointed Chairman of Grupo Popular's Board of Directors.