Precious metals remained volatile as traders digested the Federal Reserve's latest move to reinvigorate the economy.

Gold has climbed 13% this year as sluggish economic growth lifts demands for “safe-haven” investments.  The metal jumped more than 2% on Friday following last month’s disappointing jobs report, and is higher again Thursday on the heels of the Fed’s decision to enact so-called QE3.    

Hints of QE3, paired with the European Central Bank’s decision to launch a new bond-buying program, had boosted precious metal prices to multi-month highs.

Investors in gold and silver exchange-traded funds get a big boost from QE3, as the metals move inversely to the price of the U.S. dollar.

The SPDR Gold Trust ETF (GLD), which mirrors the current price and trends in physical gold, is sitting near a multi-month high. Investors have poured more than $1.82 billion into the fund over the past four weeks, according to Index Universe. GLD is up nearly 7% in the past month and more than 10% this year.

The iShares Silver Trust (SLV) backs physical silver and is up more than 18% in the last four weeks as silver prices have soared. Traders are taking notice, pouring $55.41 million into the exchange-traded fund since August 12.   

Of course, if you think the rally has run its course, there are ways to play that, too. The UltraShort Gold ProShares ETF (GLL) tracks two times the inverse performance of physical gold, the exact opposite of GLD. The exchange-traded fund is constructed to rise as the index falls while seeking to deliver twice the daily return. With the recent surge in gold, GLL is down nearly 25% since January 1.

The ProShares UltraShort Silver ETF (ZSL) is a direct bet against the SLV, seeking investment results corresponding to twice the opposite of the performance of silver bullion. The risky ZSL is down more than 30% in the past month while attracting $17.79 million in inflows since August 12.