MMAjunkie uncovered the figures by obtaining the list of disclosed payouts from the Nevada State Athletic Commission. Rousey's payday equals the record set by Conor McGregor.
Rousey is paying a price though, as a social media target for one - Nunes mocked up a tasteless photo of her pushing Rousey around as a baby. Some also believe Rousey's worth as a budding move star will suffer although America loves a redemption story.
"This is amazing. This moment is my moment," Nunes said after her victory. "She had her time. Right now, I'm the champion.
"People, let's stop this Ronda Rousey nonsense. I'm the champion here.
"I knew I was going to beat the s--t out of Ronda Rousey."
Rousey - a crossover MMA fighter from a glittering judo background - has been an extraordinary publicity magnet, and remained so despite a low key approach to her latest fight.
Nunes described Rousey's media blackout beforehand as "a big mistake" and said her career was over.
"There's no need to do that. She's a millionaire now, why does she want to keep hurting herself?" Nunes said.
It was Rousey's second consecutive knockout loss, after the shock fall to Holly Holm in 2015.
Nunes carried on the assault via Twitter, saying: "I trained for this girl since my first fight in UFC. I proved to everybody I'm the best on the planet. Now she's going to retire and do movies she's already got a lot of money.
"Forget about f***ing Ronda Rousey - I'm the real champion!"
Even Justin Bieber, who has had a weird feud with Rousey, jumped in, saying: "You just got knocked the f*** out."