The United States Natural Gas Fund (NYSEArca: UNG) and a number of other gas-focused ETFs were among the best-performing exchange-traded products last week, amid signs that gas producers are trimming production, helping to halt a three-year slide in prices.

UNG returned 5.86 percent, while the Teucrium Natural Gas Fund (NYSEArca: NAGS) added 4.44 percent and the United States Natural Gas Fund (NYSEArca: UNL) rose 4.2 percent in the five trading days ended May 10, according to data compiled by IndexUniverse. The moves all amount to signs that the gas market may well be bottoming out.

The spot gas contract on the NYMEX that expires in June has lost more than three-quarters of its value since just before financial markets crashed in 2008. UNG meanwhile lost about 95 percent of its value between then and the end of March of this year, with the extra losses linked to the costs of rolling the fund’s front-month exposure when the market is in contango.

But since about mid-April, gas prices have been rallying amid reports that big producers, including Exxon Mobil, are cutting output. Those cuts come at a time when demand has not kept pace with the production explosion of the past few years due to technologies such as hydraulic fracturing. UNG has risen upward of 20 percent in the past month.

UNG performs worse than a particular gas contract because of contango. Contango, also described as a “normal” futures curve, is when the front-month contract is cheaper than contracts that expire farther out in the future, meaning that when fund managers switch out of a front-month contract that’s about to expire, they end up paying more for the contract that replaces it, detracting from returns.

The top-performing exchange-traded product in the past week was the C-Tracks Exchange-Traded Notes on the Citi Volatility Index (NYSEArca: CVOL).

CVOL, which gained 6.79 percent, was one of many volatility-related ETPs that made it onto IndexUniverse’s top-performing list as markets turned frightful amid renewed concern about the viability of the eurozone and of Greece in particular.

Worst Performers

Indeed, the Global X FTSE Greece 20 ETF (NYSEArca: GREK) was third on IndexUniverse’s worst-performers list, declining 9.41 percent.

The two worst-performing funds were China-related: the Global X China Industrials ETF (NYSEArca: CHII) and the iShares MSCI Hong Kong Small Cap Index Fund (NYSEArca: EWHS). Both funds lost about 10 percent.

Top 10 Weekly Performers, Excluding Leverage/Inverse Funds and <1,000 Shares Traded

Disclaimer: All data as of 6 a.m. Eastern time the date the article is published. Data is believed to be accurate; however, transient market data is often subject to subsequent revision and correction by the exchanges.