5. Standard & Poors Standard and Poors, owned by McGraw Hill ( MHP) is in the spotlight as investors await its decision on a possible downgrade to U.S. debt. The rating agency has said that a $4 trillion target long-term deficit reduction plan would be necessary for the U.S. to maintain its debt rating. Any deal would have to win bipartisan support so as to convince the agency that it won't be undone, sovereign-rating chief John Chambers said in a recent webcast. But ironically, rating agencies stand to lose in the event of a downgrade, according to this list. Higher interest rates might reduce the volume of fresh debt issuances, which means less demand for the rating services of companies like S&P. Similarly the securitization market is also likely to slow as investors will likely turn skittish over riskier debt following a sovereign downgrade. IBIS World also lists Equifax ( EFX) and Experian as other companies that will be negatively affected.