????上周五夜間，標準普爾（Standard & Poor’s）決定降低美國主權信用評級，為此，華爾街掀起了一場政府保衛。目前，這一金融中樞正嚴陣以待，不斷通過電話會議來安撫緊張的投資者，淡化評級機構對市場的影響，希望能藉此避免市場周一開盤時出現過度恐慌情緒。

????但是美國遭遇降級在歷史上還是頭一遭，因此其影響仍不容小覷，而且可能會在經濟和政治領域引發廣泛的連鎖反應。盡管周一的開盤可能會吸收大部分降級的余震，但是投資者不安的情緒仍可能置華爾街的吶喊于不顧，從而引發市場崩盤。

????標普的決定對于市場來說無異于雪上加霜。標普500（SPX）上周下跌7.4%，創2008年11月信用危機以來新低。恐慌拋售是導致2008年危機的罪魁禍首之一，而它也可能是導致上周市場狂跌的原因之一，悲觀的投資者們變現手中的組合資產，將其換成現金或其他貌似“零風險”的金融工具，例如國債。

????標普將美國國債“零風險”3A級評定降級為AA+，美國國債一向被譽為投資最后的諾亞方舟之一，然而，該舉措將這艘方舟推向了風尖浪口。變現避險的趨勢可能會進一步加劇，由此引發各類資產價格的連鎖下跌。

調理預期

????但是華爾街經濟分析人士和資金經理正努力唱低標普的降級影響，聲稱降級完全在預料之中。畢竟，標普在7月份就說過，如果政府拿不出有效的方案來解決未來10年中4萬億美元的赤字問題，公司將可能向美國亮出降級牌。而且國會在大限11小時前通過的債務上限議案只涉及到了2.1萬億美元的削減。

????然而，標普在降級宣布時機上的選擇卻令很多經濟學家大跌眼鏡，當時正值市場大亂，而且兩黨組成的債務“超級委員會”還未來得及在華盛頓碰頭磋商預算削減的具體事宜。但是標普聲稱，公司對于政客們削減多達4萬億美元赤字的決心表示懷疑。

????現在，華爾街在向投資者灌輸市場一直處于降級預期當中。意思就是說市場在周一開盤時可能不會一泄千里——而且鑒于上周末可喜的就業指數，市場可能會有抬頭跡象。

????即使投資者意識到了這一點，也并不意味著他們已經做好了心理準備。降級的可怕之處在于，一些大型基金公司，由于公司有3A級證券持有比例的強制標準，將被迫拋售美國國債。這種被動拋售將成為真正拋售恐慌的導火索，并進一步將市場推向深淵。

????這一話題仍頗具爭議。但是華爾街聲稱這種強制標準實屬罕見，而且即便美國國債不再享有評級機構的最高評級，絕大多數公司仍有足夠的空間來吸納美國國債。摩根大通（JP Morgan）（JPM）的分析師認為被迫式拋售的可能性很小，而且在最糟糕的情況下，市場上被迫拋售的國債預計也只有400億美元。雖然這也是個不小的數目，但它僅占10萬億美元流通國債的0.4%。除此之外，當公司因強制標準變賣國債兌現時，公司也有可能分期分批兌現，而不是一次性兌現。

????人們選擇美國國債作為避風港的原因之一就是美國國債市場的規模。國債規模的龐大也反映了美元作為世界儲備貨幣的地位。也正因為如此，大多數外國央行必須持有美元及其國債，藉此防備本國貨幣出現不測風云，并平衡與美國的貿易流量。外國政府持有大約40%的美國國債，而且沒有任何跡象表明這些國家將于周一拋售國債。美國國債持有國前三甲（中國、日本及英國）的官員已在周末表示他們沒有拋售的計劃。

????但是很快也有交易員指出，上周，當股市因歐元主權債務危機出現恐慌拋售時，盡管投資者充分意識到了降級風險，他們仍選擇購買美國國債。美國10年期國債收益率于上周降至2.56%。

賣出之日，買進之時

????準確評估降級對國債收益率的影響是一件比較棘手的事情。如果10年期國債的市場需求趨于穩定，那么收益率應該保持不變，因為政府需要提高收益率以吸引投資者。華爾街的經濟師們一直預測10年期國債收益率可能上升25-60個基點——這樣收益率將升至3%。這跟歐洲國家現行的收益率相比仍然偏低，例如，意大利10年期國債收益率上周已升至6%。

????盡管不確定因素很多，很多資產經理正試圖安撫他們的客戶，并希望客戶們以塞翁失馬的態度來看待降級。每一次市場的重大動蕩都為那些財大氣粗的買家們提供了絕好的買進機會。

????“我們不知道周一市場開盤后的表現究竟會如何——周日晚上應該能有一些眉目——但是我們更多地將這種形勢當做是一種機遇，因為宏觀事件的對市場的影響是廣泛的，沒有針對性，”投資公司Franklin Templeton Investments的投資組合經理愛德華?博克斯向《財富》（Fortune）雜志透露說。愛德華監管的資產額達300億美元。“我們在投資過程當中將會充分挖掘基礎性研究，我們將在周一或周二中找到相應的投資機遇。”

????對于有些投資者，特別是依賴于市場波動的對沖基金來說，這種由于降級而引發的市場巨震可能是好消息而不是壞消息。與恐慌不同的是，市場可能會出現搶購熱。

????雖然這在短期內對華爾街有好處，然而從長期來看，降級終究會為華爾街及美國經濟帶來負面影響。越來越多的外國政府正逐漸采取多元化的外匯儲備政策來替代單一化的美元外匯。降級之后的幾周之內，這一趨勢將會有所加劇。例如，上周，韓國13年以來第一次購進了黃金而不是美元來作為其儲備。如果像韓國這樣的擁躉繼續疏遠美元，美國經濟將受到拖累，因為屆時漏洞就得由國內儲蓄來填補。

????華爾街自認為其從容不迫的應對和振振有詞的分析將有利于避免周一市場出現過度恐慌。但是恐慌的核心就是非理性，任何試圖以邏輯來對抗恐慌的努力都將徒勞無功。目前，從歐洲中央銀行（European Central Bank）到美聯儲（Federal Reserve），世界各國的市場信心一片低迷。貨幣是建立在信心而不是黃金之上的，美國和歐洲的貨幣系統很大程度上需要投資者的信心來維持運作。如果投資者認為該系統已經靠不住，那么人們就可能會把哪怕是輕微的評級的下調也當成經濟大難將至的佐證。

????Wall Street is jumping to the defense of the United States government following Standard & Poor's decision Friday night to downgrade its sovereign debt. The financial community is circling the wagons in an attempt to avoid a major panic when the markets reopen Monday, holding conference calls with nervous investors and downplaying the importance of credit-rating agencies in the financial markets.

????But the credit downgrade should not be taken lightly. Such an event is unprecedented and could end up having wide-reaching economic and political implications. While much of the shock of the downgrade should have subsided by Monday's opening, there is still a chance that the emotions of investors could overtake even the loudest shills from The Street, setting the markets up for a sharp fall.

????S&P's decision couldn't have come at a worse time for the markets. The S&P 500 (SPX) fell 7.4% last week, its worst performance since the dark days of November 2008 when the credit crisis went into overdrive. Panic selling was behind much of the 2008 correction and it may have also had a role in last week's market dive as concerned investors liquidated their portfolios, converting them into cash or other supposedly "risk-free" instruments, including Treasuries.

????S&P's decision to downgrade U.S. debt from its implied risk-free credit rating of AAA to AA+ has put in doubt one of the last investment vehicles considered to be a safe haven. The urge to pull more money out of the market and hide it under a mattress could therefore intensify, creating a downward spiral in prices across all asset classes.

Managing expectations

????But many Wall Street economists and money managers are downplaying S&P's move, saying that the downgrade wasn't a big surprise. After all, S&P did say in July that it would probably downgrade the U.S. if the government failed to produce a plan to reduce the Federal deficit by $4 trillion over the next ten years. When Congress finally produced a plan at the 11th hour to raise the debt ceiling, it proposed just $2.1 trillion in cuts.

????What was a surprise to some economists was the timing of the announcement, coming on the heels of a market rout and before the bi-partisan debt "super committee" meets in Washington to discuss decide on what should be cut from the budget. But S&P said that it questioned the U.S. political will to make the tough cuts needed to get close to the $4 trillion mark.

????Now Wall Street is pushing the idea that investors have already priced in a potential downgrade. This means markets probably won't go into freefall on Monday – they could even possibly strengthen given the sunny job numbers that came out at the end of last week.

????But even if investors saw this coming it doesn't mean they were prepared. One of the largest fears surrounding a downgrade is that certain large funds would be forced to sell U.S. debt on a downgrade as their investment mandates require them to hold a certain percentage of their assets in triple-A rated securities. This forced selling would then be the catalyst that could set off a major panic, sending the markets into a tailspin.

????This continues to be a controversial topic, but Wall Street is claiming that such draconian mandates are rare and that most firms have enough wiggle room to allow them to hold U.S. debt, even if it no longer carries the top rating from the credit rating agencies. Analysts at JP Morgan (JPM) believe that the potential for forced selling seems low and estimates that at the worst, the market could see around $40 billion in forced selling. That's not exactly pocket change, but it is just 0.4% of the $10 trillion of tradable U.S. government bonds available. Furthermore, it is unclear when firms must cash out of their Treasuries as mandates may call for liquidation over time as opposed to all at once.

????The sheer size of the U.S. debt market is one reason why people turn to it as a safe haven. Its largess is a reflection of the U.S. dollar being the world's reserve currency. That means simply that most foreign central banks are required to hold dollars and Treasuries to back up their own domestic currency and to balance their trade flows with the U.S. Around 40% of Treasuries are held by foreign governments and there seems to be no indication that they will be dumping them come Monday. Officials from China, Japan and the UK, the top holders of U.S. debt, have already sent signals over the weekend that they do not plan on dumping it.

????But some traders are quick to point out that last week, when there was some panic selling in the stock market in the wake of the European sovereign debt crisis, investors chose to buy Treasuries, knowing full well that a downgrade was likely. Yields on the 10-year government bond fell to as low as to 2.56% last week.

Sell-off is a buying opportunity

????Adding up what the effect a downgrade would have on bond yields is a bit tricky. If demand for 10-year bonds holds steady, then rates should hold as the government would need to offer a higher yields to attract customers. Economists on Wall Street have indicated that a 25 to 60 basis-point increase in yield may occur on the 10-year Treasury bond – pushing rates up to around 3%. That's still relatively low compared to the yields now being seen in Europe, where, for example, Italian 10-year bonds just hit 6% last week.

????Despite the uncertainty, some asset managers are trying to calm their clients by putting a positive spin on the downgrade. Any major dislocation in the market creates a buying opportunity for those with the dry powder.

????"We don't know exactly how markets will open on Monday morning – we will get some indication Sunday night – but often times we really look at these situations as opportunities, because macro events like this tend to impact markets very broadly and not very specifically," Ed Perks, a portfolio manager at Franklin Templeton Investments, who oversees over $30 billion in assets, tells Fortune. "Our investment process tries to leverage fundamental research and we will try to identify opportunities on that Monday or Tuesday."

????The sheer volatility in the market as a result of the downgrade could end up helping, not hurting some investors, especially hedge funds, which thrive on market volatility. Instead of a panic there could possibly be a rally as investors flood the market with orders.

????While that may be good for Wall Street in the short term, the long term negative effects of a downgrade could come back to haunt it and the rest of the U.S. economy. An increasing number of foreign governments are slowly diversifying their reserves away from the dollar, a process that could accelerate in the coming weeks due to the downgrade. For example, South Korea last week passed on the U.S. dollar and bought gold for the first time in 13 years to fill its reserves. If strong allies like South Korea continue to shift away from the dollar, it will be a drag on the U.S. economic growth rate, as domestic savings would have to rise to fill in the gap.

????Wall Street believes that its cool response and analytical reasoning will help alleviate any major panic on Monday. But panic is at its core irrational. Trying to counter panic with logic can be a futile exercise. What we are seeing is a loss of confidence in market systems around the world – from the European Central Bank to the Federal Reserve. The monetary systems of both the U.S. and Europe require confidence on the part of investors to operate given that the money is largely backed by faith, not gold. If investors no longer believe that system is viable, a one notch downgrade by a credit rating agency will look like a footnote in the coming economic calamity.