At the time of its completion, the Equitable Building had 20,000 employees working inside it, and 50,000 additional daily visitors. Shortly after the official opening, du Pont bought the Equitable Life Assurance Company's controlling interest. During the first year of operation, du Pont made $3 million in profit. By 1917, the building was fully occupied at an average rental rate of . The building's valuation was increased from $20.5 million to $25 million that year, because of a prosperous realty market at the time. The following year, the Equitable Office Building Corporation applied for a reduction in the building's valuation from $25 million to $18 million, due to foreclosures on other large buildings in New York City. Further devaluation occurred in 1921, when the building was estimated to be worth $11.5 million, but by the next year, the building was re-valued at $30 million, making it among the city's most valuable properties.