The US bank said forex activity had "awoken" after hibernating for most of last year, but the rise in volumes - from 2017's low base - was down to global trade and capital flows in a market still lacking clear fundamental themes.

Despite growing geopolitical risks around a possible trade war and the spectre of rising inflation, forex markets have been largely unruffled in 2018, with most major pairs trading within narrow ranges even as volatility in equities and other asset classes spiked.

Trading in the euro, yuan and rouble increased in volume last quarter by 17 percent, 54 percent, 20 percent respectively compared with 2017, BAML said in a research note.

Other currencies that saw significant rises in trading volume included the New Zealand dollar, the Australian dollar and the Thai Baht.

Banks in the $5 trillion-a-day forex market usually thrive at times of volatility, when traders can make more money as prices swing.

Market gyrations returned to forex trading in early 2018 after years of calmer markets, as investors ramped up bets on a weaker dollar and uncertainty about the end of the era of cheap money briefly stoked volatility.

Traded volumes submitted to CLS in the first three months of 2018 averaged almost $1.87 trillion, the highest since 2013, said the company, a major settler of trades in the forex market, in a statement.