Mark Volpe, the chief executive who led the Boston Symphony Orchestra into the 21st century, strengthening both its robust finances and its artistic reputation, announced on Wednesday that he planned to step down in early 2021, after 23 years in the position.

In an era when many of his peers have been buffeted by economic challenges, Mr. Volpe, 62, has kept the orchestra on firm footing by capitalizing on what he has referred to as its “multiple brand strategy”: In addition to being one of the finest symphonic ensembles in the world, it also has a lighter alter ego, the Boston Pops, and runs the successful Tanglewood music festival each summer in the Berkshires. During his tenure Boston’s endowment, the largest in the classical field, has more than tripled, to $456 million.

Mr. Volpe also served at a moment of artistic evolution — including through challenging times.

When he began at the orchestra, in 1997, Seiji Ozawa was nearing the end of a 29-year reign as music director, and some critics were calling for change. Mr. Volpe oversaw the appointment of his successor, James Levine, whose tenure began promisingly, in 2004, but ended early after his health problems led to frequent cancellations.

In 2013, the orchestra announced that the young Latvian conductor Andris Nelsons, then just 34, would be its next music director — a gamble that has paid off as Mr. Nelsons has won critical praise in Boston and seen his international stature quickly rise.