Banks flinch as derivatives head back to the future By: Reuters: Company News December 10, 2012 at 01:00 AM EST WASHINGTON, Dec 10 (Reuters) - The latest challenge to investment banks' iron grip on finance has its unlikely roots in agriculture. Read More >> Related Stocks: Bank of America CME Group Citigroup Goldman Sachs Group JPMorgan Chase & Co Mast Global Battery Recycling & Production ETF Morgan Stanley