Shares of Assured Guaranty (AGO +14.4%) surge even as S&P lowers its credit rating two...

Shares of Assured Guaranty (AGO +14.4%) surge even as S&P lowers its credit rating two notches with a stable outlook, indicating it does not plan to revisit the rating for two years unless the company's capital position changes significantly. The potential for ratings changes on the company has been an impediment to new business.