For banks at the center of the recent foreign exchange investigation, paying the $3.4 billion in fines might be the easy part.
The aftermath, filled with more intense regulations and scrutiny as well as prospects of layoffs and continuing probes into their activity, make for an even murkier future, according to those familiar with the investigation and the ensuing fallout among the misbehaving institutions.
"This is really beginning to bite," said John Alan James, a professor at Pace University's School of Business and author of multiple books on corporate governance in the banking industry. "It's time for a pause."
James is an advocate of easing the pressure on banks, which have come under continued scrutiny since triggering the financial crisis of the past decade. He believes the regulatory burden not only hurts the banks themselves but also the broader economy as institutions remain reluctant to lend.
"You've got to really think about the impact that you're having through reduced loan capacity on the national economy," he said.
Regulators, though, are determined not to repeat the ways of the loose-regulatory past, and the crackdown on a slew of traders spread through several of the financial community's biggest names put an exclamation point on how aggressive enforcement bodies have become.
Bank executives as well as sources familiar with the way the institutions are moving in the investigation's aftermath say substantial changes are expected after the fines handed down by the U.K.'s Financial Conduct Authority and the U.S. Commodity Futures Trading Commission. The entities issued harsh criticisms, with Aitan Goelman, the CFTC's director of enforcement, saying the forex trading was "corrupted by manipulation by some of the biggest banks in the world."
"We take these criticisms extremely seriously and are acting to ensure that our employees adhere to the highest standards and that our systems and controls are fit for purpose," Philip Hampton, chairman of Royal Bank of Scotland , said in a statement.
The bank said it is examining the conduct of more than 50 current and previous employees of whom it has placed six "into a disciplinary process" and suspended three of that group.
Read More Forex manipulation: How it worked
"The implications of today's settlement and of the results of the ongoing accountability and disciplinary investigations for remuneration and possible claw back will be carefully considered by the Remuneration Committee and senior management," added Ross McEwan, chief executive of RBS.
UBS would not disclose any concrete actions it had taken, but a person familiar with the matter did say the bank took "prompt and appropriate disciplinary action" against those employees who acted inappropriately.
HSBC also was expected to let go some of those involved, with reports indicating that two traders were at risk of dismissal.
JPMorgan and Citigroup also were involved. Representatives for those banks did not return requests for comment.
Some braced for future visits from regulators and even more intensified scrutiny.
"Everyone knows there is work to be done," said a person familiar with the atmosphere at HSBC, which agreed to pay the FCA $343 million. "Unfortunately it's a small number that really exhibited this kind of behavior that has had such a big impact on the business."
Some changes, like rules on social media, already have been implemented. Chat rooms on Bloomberg terminals and elsewhere featured traders referring to clients as "numpty's," British slang for a foolish person, and plots to manipulate benchmark currency exchange rates.
James, the Pace University professor, said there will be a challenge for regulators as well to tighten up the laws that govern such behavior.
"No question, everybody's going to get a hard-knocks lecture all the way down the line, and there will be an increased awareness that you could go to jail if you screw up," he said. "But be careful with your expectations, because the laws are so loose."