The Biofuels Digest Index, an index of publicly traded biofuels stocks, dropped 1.39 percent to 70.01 as ethanol equities tumbled. For the day, Biofuel Energy (BIOF) settled back 10.27 percent to $2.01, while Codexis (CDXS) dropped 6.58 percent to $1.42. Among other equities, Amyris (AMRS) lost 6.38 percent to $4.11. Overall, declines led advances 2 to 1 for the day.