©2015 Bloomberg News NOKM5S6KLVR7 (Bloomberg) — Chinese hedge funds are helping drive a commodity derivatives trading boom in the world’s biggest energy, grains and metals consumer that’s defying the worst economic growth in 25 years. Trading volumes across on the Shanghai Futures Exchange, China’s biggest commodities bourse, surged 31 percent

©2015 Bloomberg News NOBABP6KLVR7 (Bloomberg) — Wal-Mart Stores Inc. will offer a $50-a-year unlimited free-shipping service for online customers starting this summer, seeking to challenge the $99 Prime service offered by retail rival Amazon.com Inc. The service will be available by invitation only in select markets, said Ravi Jariwala, a spokesman