Chelsea boss Jose Mourinho expects Premier League clubs to spend heavily during the summer transfer window.
And Arsenal manager Arsene Wenger thinks Manchester United will be at the forefront of the buying activity.
Mourinho said: "I can imagine that this season will be like Wall Street collapsing."
Wenger predicted that United, who have already agreed a £31m deal for PSV winger Memphis Depay, would be "very active" this summer.
"We expect them to come back with some strong buys," he said.
"Every player I am offered I am told Manchester United are on their case as well."
Mourinho believes his title-winning squad will only need minor adjustments, rather than a major overhaul.
"We are in a good situation," he said. "We have stability in our squad. We don't need dramatic changes."
By contrast, Manchester United manager Louis van Gaal has been told he can eclipse the £150m he spent last summer, and has pledged to deepen his squad to avoid a repeat of the numerous injuries that have plagued the club's season.
"The most important thing is to make a balance in our selection because it's not good that I have to change the position of players because players are injured," he said.
"You can mention a lot of names, I have seen that I buy everyone in the world but it's not like that," he said.
Meanwhile, Manchester City manager Manuel Pellegrini says the club will make signings, but do not need wholesale changes to challenge for the title next season.
"Next year, we must make some changes but I don't think we are very far from Chelsea or from other teams," he said.
"I think it is important to try and work as soon as you can but to try to work in the correct way."
Pellegrini also said City were determined to retain their best players, adding: "We are not a selling team."