The Federal Reserve’s decision to cut interest rates this week may have buoyed American stocks and exchange-traded funds but is nothing but bad news for the value of the U.S. dollar.

The Canadian dollar rose to parity against the US dollar for the first time since 1976 on Thursday, aided by soaring oil prices. The U.S. dollar dropped to a record low through the $1.40 against the euro, fell 0.4 per cent to $2.0093 against the pound, lost 1.5 per cent against the yen to Y114.44 and dropped 1 per cent to SFr1.1717 against the Swiss franc.

But for investors with a diversified global ETF portfolio, there are some simple strategies that can boost returns in a weak dollar environment.

The easiest way to play the weak dollar trend is with international or country specific ETFs. They are not hedged against the dollar so that strength in the underlying currency, such as a stronger Singapore dollar captured through the Singapore ETF (EWS), boosts returns for U.S. dollar-based investors.

Rydex also offers a series of foreign currency ETFs such as the CurrencyShares British Pound Sterling (FXB), the CurrencyShares Euro (FXE), and the CurrencyShares Canadian Dollar (FXC).

A couple of Chartwell's seven model ETF portfolios have a small position in PowerShares DB G10 Currency Harvest (DBV) which is up nicely this year. It tracks 10 currencies, going long on the three top tier currencies with the highest interest rates and going short on three currencies with the lowest interest rates. DBV is currently long on the Australian dollar, the New Zealand dollar and the Pound sterling and short on the Japanese yen, the Swiss franc and the Swedish kroner.

This is not a bad return but relying primarily on interest rates ignores other key factors. It is also a good idea to have some emerging market currency plays in your portfolio. Take for example, the Brazilian real and the Brazil iShare (EWZ). Brazil has been on a spree of cutting interest rates over the past two years and its currency has strengthened considerably. Consumer demand, exports, and investment have been fueling economic growth and a stronger currency has helped keep a lid on inflation. The real has appreciated sharply against the US dollar.

Then there is the PowerShares U.S. Dollar Bearish Fund (UDN) that track the New York Board of Trades U.S. Dollar Index. This index is the most popular measure of the dollar against other currencies; the Euro has a 58% position; Japanese yen 14%; British pound 12%; Canadian dollar 9%; Swedish krona 9%; Swiss franc 3%.