估计很多人都没有料到，因为事前Moody's以及Fitch都确认了美国的AAA评级，虽然展望为负面。美国周五当天标普通知美国政府就要下调评级，但美国政府指出标普的分析计算有误，但标普还是最终履行了之前的“诺言”，即除非美国之后10年减赤4万亿，否则美国的AAA会失去（历史上第一次）。

首先，美国国债几乎是国际金融的基石，如果基石有动摇，影响自然不用说。引用Martin Weiss的话：

Deception #2. When S&P, Moody’s, and Fitch downgrade the U.S. government’s debt, Washington and Wall Street will try to convince you that it’s not going to have much impact.

False!

Standard & Poor’s has already said that the downgrade will directly impact government-owned and government-sponsored agencies: Ginnie Mae, Sallie Mae, Fannie Mae, Freddie Mac, and many more.

S&P has also promised that a U.S. debt downgrade could precipitate downgrades of up to 7,000 municipalities.

What they have not told you is that many corporate bonds could also be subject to downgrades.

Why? Because the companies that issue these bonds rely on U.S. government subsidies, contracts, financial guarantees, bailouts, and more. Or they do business with other companies that rely on the U.S. government.

And in a broader sense, they operate in a country — the United States — where the government’s credit rating is a key factor in virtually every financial transaction.

So a downgrade for the U.S. government is inconceivable without a chain reaction of downgrades in virtually every business sector.

Plus, there’s one more explosive fact that S&P has chosen not to highlight in public:

The Impact of a U.S. Debt Downgrade on the
Ratings of Thousands of Banks and Insurers

Throughout modern history, thousands of U.S. banks and insurers have held large portfolios of U.S. Treasuries, government agency bonds, municipal bonds, and corporate bonds.

And almost invariably, it has been assumed that, with the exception of junk bonds, these holdings were a key factor in helping the financial institutions get better ratings.

What happens to their ratings if a substantial percentage of their bond holdings is downgraded? The answer should be obvious: The financial institutions themselves must ALSO be downgraded.

Result: Mass downgrades for thousands of U.S. banks, credit unions, and insurance companies.

How vulnerable are they to this collective disaster? The table below, based on the Fed’s latest data, gives you the answer in a nutshell:

Why Ratings of Thousands of U.S. Banks and Insurance
Companies Are Vulnerable to a U.S. Debt Downgrade
http://images.moneyandmarkets.com/2164/img2.jpg& Poor）下调美国债务评级到AA+" TITLE="简谈标普（Standard & Poor）下调美国债务评级到AA+" />
Data source: U.S. Federal Reserve’s Flow of Funds Accounts of the United States. For banks and S&Ls, the numbers shown combine the totals from the Fed’s tables L.110 and L.114. For credit unions, see table L.115. And for insurance companies, see tables L116 and L117.

Start with their holdings in Treasury securities. According to the Federal Reserve, banks and savings & loans hold $216 billion; credit unions have $21 billion; life insurers have $156 billion; and property-casualty insurers have $93 billion.

Total Treasuries held by U.S. financial institutions: $486 billion, a very substantial sum.

But those holdings are small in comparison to what banks and insurers have piled up in bonds issued by a raft of U.S. government agencies: Banks have $1.5 trillion, according to the Fed. Credit unions — $162 billion. Life insurers — $386 billion. And property-casualty insurers — $116 billion.

Total government agency securities held by U.S. financial institutions: A whopping $2.2 trillion, all of which will be immediately subject to downgrades by the major rating agencies as soon as the U.S. loses its top-notch credit rating.

And that’s STILL not the end of it.

U.S. financial institutions also have $725 billion in municipal bonds and $2.9 trillion in corporate and foreign bonds, most of which would probably also be subject to downgrades over the next few months.

All told, U.S. financial institutions now hold an astonishing $6.3 trillion in securities subject to immediate or future downgrades in the wake of a U.S. government debt downgrade.

Of course, the banks and insurers invest in other things besides government and corporate bonds: Mortgages, commercial loans, and more add up to total financial assets of nearly $19 trillion.

It remains to be seen what percentage of those assets will also wind up on the rating chopping block. But even assuming those other assets never wind up on the ratings’ chopping block, here’s the bottom line:

A whopping ONE-THIRD of all the financial assets of all U.S. financial institutions is potentially vulnerable to mass downgrades.

Bottom line: If folks in Washington or Wall Street try to tell you this isn’t a big deal, tell them to take a hike.

另外一方面讲，欧洲的法国，德国等难道比美国的情况更好吗？事实上，如果欧元区债务危机进一步扩散，为了拯救西班牙和意大利，德国和法国为了扩大EFSF就得承担起相当于50%GDP的债务，如果进而法国出问题，德国就得承担起133%GDP的债务。当然，那时候欧洲可能没有一个AAA了。据德国明镜报8月6日：

• German Govt: Italy Too Big For EFSF To Save - Spiegel
• German Govt: Doubts Whether Tripling EFSF Would Help It Save Italy
• German Govt: Italy Must Make Savings, Reforms To Exit Crisis - Spiegel
• Italy Debt Guarantee Could Raise Doubts Over Germany's Finances - Spiegel
• German Govt: EFSF Should Only Help Small, Mid-Size Countries - Spiegel
  

所以，有可能美国国债的避险效应因为标普的下调动作而降低了。那么，黄金也许得到比较强的动力。毕竟，黄金的整个升势还没有表现出最后的疯狂。（不做投资参考）