Some 83% of asset and wealth management firms are somewhat or extremely concerned about over-regulation this year, according to a global survey of CEOs by PwC.
The Markets in Financial Instruments Directive II (MiFID II) is thought to be most threatening in Europe, while the Department of Labor Fiduciary Rule is most concerning in the US.
PwC said these regulations are putting further pressure on asset management fees and demanding greater transparency, which is expected to squeeze margins over 2018.
Geopolitical uncertainty was the next biggest worry, cited by 80% of the respondents, while tax changes and cyber security threats were highlighted by 77% and 73% respectively.
"CEOs are definitely beginning to appreciate both the magnitude of potential disruption in its various guises," PwC UK asset and wealth management leader, Elizabeth Stone, said.
MiFID II came into force across the EU at the beginning of the year, and is expected to be one of the final pieces of regulatory reform following the 2008 banking crisis.
It is intended to make financial markets more efficient, resilient and transparent, by increasing the amount of information available to investors while reducing the use of dark pools and OTC trading.
IHS Markit and Expand estimate that global banks and asset managers have spent at least $2.1bn (£1.5bn) in order to comply with the 1.7 million paragraphs of rules.
The regulation is also expected to dramatically impact the investment strategies of pension schemes, with the Pensions and Lifetime Savings Association (PLSA) publishing a guide in response.
"Schemes will have to deal with changes affecting everything from the way research is paid for, to the disclosure of cost and best execution information," PLSA investment and defined benefit policy lead, Caroline Escott, said.
"Although this poses challenges, it also offers an opportunity for in-depth consideration of the value of schemes' fund management services."
