The UK's financial regulator is to investigate whether consumers are getting value for money from companies who invest their savings and pensions.
The Financial Conduct Authority (FCA) will examine asset managers, and individuals who provide advice.
The inquiry, external will focus on how investors choose a manager, and whether there is sufficient competition between them.
The level of charges - and how well those charges reflect performance - will also be scrutinised.
Consumer groups have complained that there can be a wide variation in fees, and they are not always transparent.
"Our market study aims to ensure that both retail and institutional investors can get value for money when purchasing these services," said Christopher Woolard, the FCA's director of strategy and competition.
The announcement was welcomed by the investment industry.
"We agree it is essential the whole investment chain functions effectively for its clients," said Guy Sears, interim chief executive of the Investment Association.
"We welcome the FCA's decision, alongside its core focus on investment managers, to also consider the role of distributors and investment consultants."
The FCA will publish its initial findings in the summer of 2016, and a final report early in 2017.
