After controversial financial market transactions by leading central bankers, the American Federal Reserve (Fed) adopted strict rules for financial market transactions by senior employees.
The central bank's decision-makers and employees in higher positions should no longer invest in individual stocks, bonds or derivatives, the Fed announced on Thursday.
This means that they are now limited to buying diversified investments such as funds, it said.
The aim is to avoid possible conflicts of interest of the central bankers - or even the appearance of such conflicts.
"These stringent new rules are setting a new standard to reassure the public we serve that all of our senior officials are focused solely on the public mandate of the Federal Reserve," said Federal Reserve Chairman Jerome Powell.
As a further precautionary measure, those affected would generally have to register planned transactions 45 days in advance and have them approved.
The investments would have to be held for at least one year.
In times of heightened tension on the financial markets, transactions are also prohibited.
The presidents of the regional branches of the Fed are now obliged to disclose financial transactions within 30 days - as is already the case for leading representatives of the Fed.
Two regional presidents were recently criticized for acting on their own account last spring when the Fed supported the financial markets with a significant easing of monetary policy.
Both are now divorced from office.