When it came time to get ratings agencies to evaluate these new securities so they could be sold, senior tranches could be rated much higher than ones representing subordinated debt, even though they were all backed by the same mortgages or securities. The problem was compounded by the abstraction of CDOns: a security could be an amalgamation of AAA rated amalgamations of bad mortgages. Billions of dollars have been gained and lost on the merit of ratings changes, security ratings are very serious business. Why, then, were these tainted CDOs traded as AAA? It represented a massive failure to recognize risk! To put it another way, "about 90 per cent of the products rated as investment grade by Moody’s in 2007, for example, have since been relegated to junk status. By 2007, the housing boom was already gone. The smart money had seen the mess coming two years ago [9]. How could they be that wrong? The answer lies within incentives: everyone from bank to investment group to investor was making a lot of money, and no individual party wanted to incur the wrath of the rest by being the one to sound the alarm. A credit rating agency collects fees from the creator of the security. A credit rating agency that downgraded its rating of assets held by its major business partners would provoke hostility and lose business. Thus, warnings were ignored.