ETFS Physical Platinum Shares (NYSEArca: PPLT) is the best-performing commodity ETF this week with a gain of more than 4% as talk of the U.S. minting a $1 trillion platinum coin to avert the debt ceiling just refuses to die.

“In just a few weeks, the ‘platinum coin’ option has gone from a wacky idea to becoming the subject of serious discussion among academics, market participants and, yes, some politicians. In itself, this evolution says a lot about the state of U.S. Congressional dysfunction, especially when it comes to economic governance,” writes Mohamed El-Erian, CEO and co-chief investment officer of PIMCO, at

The platinum ETF was up for the fourth straight session Friday amid the lingering debate and grandstanding over the platinum coin.

Elsewhere in ETFs, Spain and Italy were also among the top gainers this week as Europe continues to outperform the U.S. [Why the Eurozone ETF is Trouncing the S&P 500]

In the major U.S. equity indices, the S&P 500 was on track for a slightly weekly gain of 0.2% in afternoon trading Friday, while the Dow added 0.3% and the Nasdaq Composite climbed 0.6%.

Other top performers in ETFs this week included funds for Vietnam, corn, solar energy and coffee. Market Vectors Vietnam ETF (NYSEArca: VNM) was still on track for a weekly gain of 4% despite tumbling about 4% on Friday.

The Vietnam has rallied sharply since the beginning of December but saw some of its premium to net asset value unwind in Friday’s sell-off.