Image: Wayfair.

The stock market sank again Wednesday, continuing its poor performance to begin 2016. Even though the market ended well off its lows of the day, the S&P 500 has still fallen 9% since the beginning of the year, and the Dow is down nearly 10%. Oil prices tumbled again, and market participants pointed to continued nervousness overseas about the global economy's ability to weather the current storm. Yet even on a gloomy day, Southwestern Energy (SWN 2.71%), Spirit Airlines (SAVE -2.90%), and Wayfair (W -8.36%) were able to post substantial gains on Wednesday.

Southwestern Energy picked up 13%, surprising casual observers in light of oil's drop. Unlike many energy companies that shifted their focus away from natural gas toward crude oil in recent years, Southwestern Energy has mostly remained concentrated on gas. Investors also appear much more confident in the prospects for the natural gas market, given solid demand for the fuel from utilities using it for electrical generation and for delivery to heating customers. With natural gas prices hovering just above $2 per million BTU, investors haven't seen much strength in that market as well, but on percentage terms, the declines haven't been nearly as severe as in the oil markets. Whether the shift within energy will continue is uncertain, but for now, Southwestern and several of its peers have earned a reprieve from their share-price declines recently.

Spirit Airlines climbed 11% after filing an investor update with the SEC late yesterday. The airline said that fourth-quarter operating margins would come in at around 22.5%, up five percentage points from its previous guidance because of higher sales and lower costs than expected. Even though Spirit's markets demand extremely low fares and face severe competition, the discount airline has done a good job of adapting to a low fuel cost environment and minimizing overhead costs. Moreover, the company is growing, with estimates that its capacity will rise about 20% in 2016 from last year's levels. With expectations for deliveries of more than 90 aircraft by the end of 2016, Spirit is counting on continued healthy expansion in the travel market to help support its growth this year and beyond. So far, investors like what they're seeing from the company based on its recent results.

Finally, Wayfair gained 10%. The e-commerce-based furniture and furnishings company received an upgrade from analysts at Citi, who cited positive factors including its share-price gains and its history of beating its estimates and boosting its guidance in their favorable comments on the stock. Some investors have been skeptical about Wayfair's ability to be profitable because of the challenges involved in fulfilling online orders for large items that require special shipping and handling treatment. So far, though, the company has done well in attracting a loyal customer base, and bullish investors expect the solid results that Wayfair has posted in the past to continue when it reports its performance for the key holiday quarter in the near future.