Although Fink and Gross are both known as bond experts, they have taken their careers and their companies in very different directions. Gross has continued to focus on investing, while Fink has developed into more of a traditional CEO, leaving the day-to-day investing to others. Fink early on took his company in more directions, adding consulting and stock investing, something Pimco has only recently done.
On the rare occasions when Gross — the brainy, yoga-loving homebody — has ended up on the same stage as Fink — a globe-trotting power executive — the differences are obvious.
"Bill probably has a better quality of life than I do," Fink said. "And more hair too."
The large market share that BlackRock and Pimco command means that anyone interested in issuing bonds needs to consider their opinions.
"If you don't treat them well, or you don't provide them what they want, they have the ability to punish you by not doing business with you," said Jacobson, the Morningstar analyst.
This has led to fears among some that the companies hold too much sway over the markets. The concern was underscored when both men were advising the government during the financial crisis and stood to gain from some programs they were helping design.
But Jacobson said that although both men ended up doing well during the financial crisis, none of the fears of wrongdoing have been substantiated.
"Compared with so much else that goes on in corporate America, they are practically choir boys," Jacobson said.
The joint attention they have received has not been because of wrongdoing but because of their contrasting views.
Most famously, this year, Gross led Pimco to take a big bet against U.S. Treasury bonds.
BlackRock took the opposite view. While Pimco was dumping Treasuries, BlackRock was buying, a move that proved immensely profitable.
Because of Gross' bad bet on Treasury bonds, Pimco's largest bond fund experienced a rare underperformance against rivals. In one of his famous letters to Pimco investors, he wrote, "I'm just having a bad year."
One of BlackRock's biggest mistakes came in 2006 when it used money from the California Public Employees' Retirement System to help buy the Stuyvesant Town apartment complex in Manhattan. The deal ended up losing CalPERS $500 million.
But these have been rare low moments for both men.
"What is remarkable about us is the longevity of our careers, and the successes we've had," Fink said.