Banks must apply the same standards of surveillance and conduct to staff working from home or in the office during the pandemic and in future as working practices change, Britain's Financial Conduct Authority said.
The FCA is paying particular attention to how inside or sensitive information is handled at a time when the volume of mergers, and issuance of shares and debt is rising sharply to keep companies afloat.
There is a risk of less self-policing among front office staff working from home, said Julia Hoggett, the FCA's director for market oversight.
"This is especially true of firms which invest in distressed debt markets where inside information is not always as clearly demarcated as in equity markets," she added.
What constitutes inside information may change radically during the pandemic, the FCA's director for market oversight said.
It could now include knowledge that an entire business' operations would have to shut or reopen, whether a company has used a government-backed relief scheme, or details about the pace of cashflow burn, she said.
"This requires companies and their advisers to be alert to what information is likely to drive their valuation and to bring a potentially wider range of issues to be discussed at their disclosure committees," Hoggett said.
Banking staff began working from home in March when the UK economy went into lockdown.
Some staff began returning to offices over the summer but a resurgence in the virus has forced many to work from home again.
"We will have to navigate a huge amount of change over coming months - that will no doubt include both hybrid ways of working and, indeed over time, potentially long-term changes to the way that we all work," said Hoggett.
"Our expectation is that, going forward, office and people-working-from-home arrangements should be equivalent," she told a City & Financial online event.