Another round of selling hit Wall Street Tuesday after China devalued its currency. China’s move reignited concerns over the health of the world’s second-largest economy. China airline stocks sold off on the news, but U.S. airlines outperformed, thanks to a sharp drop in oil prices. Benchmark crude oil hit a six-year low, falling $1.88, or 4.2%, to $43.08 a barrel. SkyWest (SKYW) scored a new high, rising 0.46 to 17.74 in heavy volume.