The Biofuels Digest Index, an index of publicly traded biofuels stocks, dropped 1.20 percent to 68.62 as advanced biofuels slumped. For the day, Gevo (GEVO) plunged 23.14 percent to $1.99 after a 1-15 reverse split, while Codexis (CDXS) slumped 3.75 percent to $4.56. Among other equities, Solazyme (SZYM) fell 2.43 percent to $3.81. Overall, declines led advances by a 3 to 2 ratio for the day.