Stock prices dropped by 20 percent from September 24 to October 1, while trade was minimal. Between January 1870 and September 1870, only 4 million shares of stock were exchanged. Dozens of brokerage firms went bankrupt, those who bought paper gold from Fisk's gold room going unpaid. Farmers, who constituted 50 percent of the country's workforce, suffered the worst: wheat prices on the Chicago trade fell from $1.40 to $0.77 a bushel, corn dropped from $0.95 to $0.68, and other commodities such as rye, oats, and barley had similar losses. The New York Tribune reported that goods ready for export could not be shipped. American agriculture went into steep decline and would be plagued by tight money and dwindling markets for years to come. Grant's and Boutwell's actions to break the "Gold Ring", however, kept the Wall Street panic from growing into a national depression. Butterfield was allowed to resign from the U.S. Treasury without an investigation in October, 1869.