The S&P 500 Index may have another 24% to fall by year-end, if the past 150 years of financial-market history are any guide. That's according to Societe Generale, which calculates the benchmark gauge may need to tumble as much as 40% from its January peak in the next six months to hit bottom. Overnight, US Treasuries rallied after another batch of economic data fell short of expectations, ratcheting up recession worries. The S&P 500 ended almost 1% higher as the decline in yields made stocks relatively more attractive. Equity futures signal cautious starts in Japan, Australia and Hong Kong.