“They made bankers billions of dollars before helping to blow up the global economy in 2008, living up to Warren Buffett’s description of derivatives six years before as “weapons of financial mass destruction.” After the crash, regulators set to work to make them less dangerous, through changes that in the process would make them less profitable. That set off a lobbying war on a titanic scale. Regulators say they succeeded in fundamentally altering the $633 trillion over-the-counter derivatives market, moving most of the trades onto open exchanges that take the place of the private dealing that was the norm. Critics say the new trading structure isn’t as competitive as the government first hoped. And nobody knows whether the dangers were truly put to rest or just shifted elsewhere…”