That means the dollars Yellen’s Fed is removing could be compensated for by cheap euros from the European Central Bank. The result may be enough cash sloshing around to underpin this year’s run-up in risk assets even if the Fed begins mulling higher interest rates too, says Marios Maratheftis, head of macro research at Standard Chartered Plc in Dubai.

“If any central bank can take over the Fed’s role in terms of its impact on global liquidity, it’s the ECB,” according to a June 30 report by Maratheftis and colleagues David Mann and Italo Lombardi.

They reckon the relative importance of the Fed in propelling liquidity worldwide has fallen since April 2013. During the last year it has slowed the bond buying it began in December 2008 as financial panic gripped the world. Regulators’ more recent demands that banks increase reserves also may mean a higher money supply in the U.S. boosts liquidity less elsewhere too.

For every $10 billion increase in the U.S. money supply, there is now a $20.5 billion increase globally, down from $24.4 billion a year ago, according to the Standard Chartered economists. Meantime, for every $10 billion rise in the euro area’s money supply there’s a $19.7 billion boost globally, up from $18 billion.

Fed Impact

With its quantitative-easing program winding down, the Fed has gone from having 35 percent more impact than the ECB a year ago to 5 percent today. The economists also calculate that to keep global money supply stable, the ECB would need to provide $10 billion of liquidity for every $9.5 billion withdrawn by the Fed.

That may happen. Standard Chartered predicts the euro area’s Frankfurt-based central bank will start its own asset- purchase program before the end of this year.

“Focus should start shifting from the actions of the Fed to what the ECB will do,” said Standard Chartered. “The ECB’s decision on QE may be domestically driven, but its impact will be global.”