Image: PetroChina.

With stock markets in mainland China closed for a week of holidays, investors in Asia are focusing on the Hong Kong market as a proxy for Chinese stocks. On Wednesday, Hong Kong posted huge gains, as the Hang Seng Index (HSIINDICES:^HSI) soared 684 points, to 22,516. For those who've followed the markets during the past year, the source of the gains was somewhat surprising, as long-battered energy stocks provided huge upward support to the Hang Seng and the broader market.

Oil bounces back
After a terrible third quarter, the oil market has shown some signs of life, as prices for Brent crude climbed to nearly $52 per barrel after falling as low as $44 during the August financial-market swoon. Fundamentally, some signs that plentiful supplies might finally start to get back into balance with demand gave energy-market investors greater confidence, and that spilled over into the stock market.

In particular, Chinese energy stocks posted the greatest gains. Shares of PetroChina (NYSE:PTR) jumped 9% in Hong Kong trading overnight, while CNOOC (NYSE:CEO) saw even more substantial gains of nearly 14%. A host of other companies specializing in energy and natural resources also bounced back from recent poor performance. Financial stocks also performed well, with various banks in the Hang Seng posting gains of as much as 5%.

Only a handful of companies held back the Hong Kong stock market. Sands China led the decliners, with a drop of about three-quarters of a percentage point; but after its impressive 20% rally during just the past week, few investors seemed concerned about the minor setback.

What's ahead for China?
Despite Hong Kong's strong performance, investors are looking forward to the reopening of mainland Chinese markets tomorrow. One question that both markets will have to face is whether a rebound in the natural resources sector is an overall positive.

Higher commodity prices obviously help companies like CNOOC and PetroChina, but they also make it more expensive for various manufacturing companies to do business. In order to benefit, manufacturers will have to be able to pass through any increased costs to their own customers, and that will require a broader rebound throughout the commodity sector rather than simply in the energy arena.

In the absence of more pressing news, most market participants in Asia are keeping their eyes on U.S. monetary policy and economic strength, looking for signs of any reversal in the trends that have continued for years. The level of uncertainty has definitely risen in recent months, and that, in turn, could keep markets volatile for the foreseeable future.

Still, the gains in Hong Kong have reminded investors that an eventual rebound from a tough year in the China region is possible. Those who are willing to take risks at current levels might well see a long-term reward in the end.

Dan Caplinger has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.