"These are not necessarily buys, but an area where there will be an impact" from currency moves, he said.

Betting on currency moves is risky, but that hasn't stopped millions of Americans from investing in currencies - usually without knowing what they're gambling on.

Any such currency move would set off a storm in Washington, risking a trade war.

But given the possibilities of currency moves, economic changes or political shifts in the issuing countries, the fund's share price may be volatile.

Although professional traders buy and sell on a daily basis, amateurs can take a longer term view if they study the overall direction of currency moves.

But big currency moves can also cause big problems.

The government this week denied that such a currency move was imminent.

Anyway, he said, "hedging assumes you can forecast currency moves, but they're unpredictable."

But Beijing worries that sharp currency moves could be too much of a shock for the economy, perhaps even forcing companies to lay off workers.

Selective Rallies' This means that a fund should be hedging against such currency moves, although the cost does reduce potential returns.