A decade after the crisis, optimism and caution on Wall Street A trader on the New York Stock Exchange remembers the "ruthless" day when the Lehman Brothers collapse precipitated the worst global economic crisis since the 1930s, and explains that a "strong foundation" has been built since then, with the market now "too big to fail". According to a financial analyst, the risks to the global economy now lie elsewhere, with shadow banking and the prospect of an all-out trade war. IMAGES AND SOUNDBITES