Ambac sold itself insurance on residential mortgage-back securities, piling on risk.
Ambac's chance of avoiding a delisting rose after the stock price jumped.
Ambac investors are converging on the stock, apparently unaware of the risks.
Ambac looks like it's heading toward bankruptcy, but there are many reasons why it won't.
A state insurance regulator takes control of Ambac, leaving bondholders and stockholders up in the air.
Ambac says it's forged provisional agreements as a state insurance regulator takes control of the company's operations.
Ambac buckled under pressure to accept an agreement to put about $35 billion of assets into a separate account overseen by a regulator.
Bank of America, Citigroup and other banks face claims of fraud and misrepresentation from insurers over mortgage-backed securities.
AIG, MetLife and Conseco are some of the best-performing insurance stocks in the past month.
Washington DC insurance regulator, citing errors, rescinds a previously approved price rise for a health insurer.