An overdue sell-off flusters exchanges and sobers investors

　　遲來的拋售攪亂了股市，也驚醒了投資者

　　IT WAS almost inevitable something bad would happen. Barely a ripple had disturbed the smooth surface of financial markets since May last year. But on February 27th share prices were suddenly hit by a wave of selling.

　　是福不是禍，是禍躲不過。自從去年5月以來，金融市場靜如止水，鮮有波動。然而在2月27日，一股拋售浪潮導致股票價格一瀉千里。

　　It is always possible to find plausible reasons for a sudden stockmarket fall after the event—less easy to pick them beforehand. The immediate catalyst for this week's troubles appeared to be a near-9% fall in the Chinese stockmarket, itself triggered by stories that the authorities were about to clamp down on speculation. But the truth is that investors were simply looking for excuses to take profits.

　　人們總能為股市的突然下跌找到合理的解釋，然而做事后諸葛容易，做到曉之于未然難度就大多了。政府準備打擊投機活動的傳言引發(fā)中國股市暴跌近9%，這似乎是本周市場動蕩的直接誘因。然而真相是，這只是投資者為收割利潤尋找的借口。

　　A decline looked overdue. Wall Street had enjoyed its longest period without a 2% daily fall for more than five decades. Margin debt—the money sharebuyers borrow from brokers—had just passed its previous peak, recorded during the dotcom bubble. Risky assets, from high-yield corporate bonds to emerging-market debt, were offering historically low yields.

　　其實這樣的下跌早就該發(fā)生了。美國股指日跌幅小于2%已維持了50多年，超過史上任何一段時期。保證金負債量(margin debt，股票買家向經(jīng)紀人借入的資金)超過了此前互聯(lián)網(wǎng)泡沫時創(chuàng)下的紀錄。高收益公司債券和新興市場債務等風險資產(chǎn)提供的收益也創(chuàng)下歷史新低。

　　When it came, the sell-off was dramatic. At around 3pm New York time on February 27th, the Dow Jones Industrial Average was down by a couple of hundred points. In less than a minute, it plummeted another 200 points—a rate of decline that traders said was unprecedented.

　　股票拋售一來便來得如此猛烈。2月27日下午3點左右，道瓊斯工業(yè)平均指數(shù)已下跌幾百點，然后在不到一分鐘的時間內，道指直瀉200點；速率之快，史無前例。

　　The speed of the fall was caused by a tabulation delay. The data-systems arm of Dow Jones, which calculates the average, had been unable to process orders quickly enough as they surged during the afternoon. At 3pm the firm switched to a back-up system in an effort to unblock the pipe. This did the trick, but caused a massive instantaneous fall in the average as it readjusted after the delay.

　　下跌如此之快起因于“計算延遲(tabulation delay)”。由于計算平均指數(shù)的數(shù)據(jù)系統(tǒng)來不及處理當天下午大量涌入的訂單，為暢通道路，道瓊斯公司與3點啟用了備用系統(tǒng)。新系統(tǒng)起了作用，卻引發(fā)重新調整后的道指瞬間大幅下挫。

　　This was not the only problem. Floor traders were unable to keep track of computer-driven orders, particularly those selling exchange-traded funds—baskets of stocks linked to an index. At its low, the Dow was down 546 points, among the worst points falls in its history.

　　問題不止這一個。場內交易商(floor traders，指在交易所場內主要為自己或自己占有份額的帳戶進行交易的交易所成員—譯注)無法追蹤電腦驅動的訂單，特別是賣出上市交易基金(ETF，盯住某一指數(shù)的股票組合)的訂單。當日道指最大跌幅達546點，成為史上最大單日跌幅之一。

　　None of this was good news for John Thain, the NYSE's chief executive. He was seen on the trading floor just after the 3pm meltdown, looking flustered and spurning interview requests. With competition between traditional exchanges and electronic networks hotter than ever, the last thing he needs is questions over the robustness of the NYSE's technology.

　　對紐約證交所的首席執(zhí)行官約翰·塞恩(John Thain)來說，沒有一條是利好消息。下午三點的大崩盤后不久，他便出現(xiàn)在交易大廳里，看上去驚慌失措的他拒絕任何采訪。在傳統(tǒng)的交易所和電子網(wǎng)絡之間的競爭愈發(fā)激烈的時候，他最不希望聽到的就是有關紐約證交所是否還具有活力的質疑聲。

　　Inevitably, Wall Street set the tone for the rest of the world, with European, Asian and emerging markets falling heavily in its wake. But on February 28th the American market showed signs of stabilising.

　　華爾街為世界其它地方的股市定下了基調：歐洲、亞洲和新興市場的股市不可避免地緊跟著大幅下跌。但在2月28日，美國股市出現(xiàn)回穩(wěn)跡象。

　　Will that be it? Certainly those investors interested in the “fundamentals” can find things to worry about. Tensions over Iran's nuclear programme are still high, and the oil price is $10 a barrel above its recent lows. The recent defaults in the subprime mortgage market may be affecting other bond investors and cutting off credit to the housing market. Some recent American economic data have been weak and Alan Greenspan, the former chairman of the Federal Reserve, has mused publicly about the possibility of a recession.

　　但果真如此嗎? 注重觀察“經(jīng)濟基本面”的投資者當然有擔心的理由： 伊朗核計劃引發(fā)的緊張局勢不見緩和；每桶石油的價格比近期最低價高出10美元。最近次優(yōu)房貸市場上的違約現(xiàn)象不僅可能會給其他債券的投資者帶來不利影響，還會切斷房市的信貸來源。最近的數(shù)據(jù)顯示美國經(jīng)濟走弱，美聯(lián)儲前主席艾倫·格林斯潘也在公開探討美國經(jīng)濟衰退的可能性。

　　His successor, Ben Bernanke, did best to allay fears of an immoderate slowdown. If he is wrong, he can always start lowering interest rates. The "flight to safety"has already caused Treasury bond yields to fall, cutting the borrowing costs of homebuyers.

　　而他的繼任者本·伯南克則竭盡全力緩和經(jīng)濟衰退的預期所帶來的緊張氣氛。如果他出了錯，他總還有個殺手锏——降息。資金向安全資產(chǎn)轉移的現(xiàn)象(flight to safety)使得國債收益率下跌，降低了購房者的借款成本。

　　But it may be the internal dynamics of the markets, not the evolution of the wider economy, that decides whether this is a brief shakeout or the start of a serious correction. Periods of low volatility tend to encourage risk-taking. Hedge funds have a natural inclination to buy higher-yielding (and thus riskier) instruments and sell low-yielding assets, since this delivers a positive income or “carry”. When the market falters, these positions rapidly lose money. For example, the modest rise in the yen—2.3% against the dollar on February 27th—wiped out about half the annual interest gain accruing to investors who sold yen and bought dollars. Those who gambled on the “carry trade” may decide to cut their losses.

　　然而，這次暴跌究竟是一時的動蕩，還是市場大幅調整的開端，取決于市場內部的變動，而非整個經(jīng)濟體的發(fā)展。波動率較低的時期風險交易旺盛。對沖基金天生傾向于賣出低收益的資產(chǎn)，購進高風險高收益的金融工具，以此取得正收益或者“套利”。當市場出現(xiàn)動蕩，這些頭寸將迅速貶值。比如2月27日日元對美元小幅升值了2.3%，賣出日元買進美元的投資者積累下來的年利息所得瞬間被抵消了一半。這樣，這些“套息交易”的玩家們可能會決定拆倉止損。

　　As they do so, other investors may hurry to shift their feet. Investment banks use “value-at-risk” models which mean that, when volatility rises, they cut the capital they allocate to trading. This usually means selling assets. So a sudden jump in volatility tends to generate further volatility. "The sell-off was merely a warning shot," says Chris Watling of Longview Economics, a strategist who recently forecast a correction. “"nvestors should expect further selling in coming weeks."

　　如果它們果真如此，其他投資者也會迅速轉移資金。投行廣泛采用“風險價值”模型：當市場波動率上升時，它們將減少交易資金，而這通常意味著減持資產(chǎn)。由此，波動率的突然上升將會導致市場上更大的波動。長景經(jīng)濟顧問公司(Longview Economics)的策劃師克里斯·沃特林(Chris Watling)最近預測將有一次市場調整：“這次拋售還只是個警告，未來幾周這還將愈演愈烈。”

　　What matters is how many actors have all made the same bet. One of the oldest market mistakes is the assumption that you can get out of a position as easily as you entered into it. According to Goldman Sachs, the latest jump in the Vix (a measure of stockmarket volatility) took it eight standard deviations from its average. If conventional models are correct, such an event should not have happened in the history of the known universe. Then again, the move in energy prices that caused the collapse last year of Amaranth, the hedge fund, was a nine standard-deviation event. Perhaps modellers do not know the universe as well as they would like to think.

　　關鍵是參與者中有多少進行了這般相同的賭博。好進就好出的想法是金融市場上最老套的錯誤之一。高盛的報告顯示，波動率指數(shù)(Vix，衡量股市波動性大小的指數(shù))最近上升了800點。如果常規(guī)的模型無誤的話，這在已知世界的歷史中本不該發(fā)生。其實歷史早在去年就上演過一次，能源價格的變動導致了對沖基金Amaranth的破產(chǎn)，當時Vix的漲幅達到了900點。

　　This is what makes markets prone to nasty surprises and it explains why investing with borrowed money can be dangerous. If some bank or big hedge fund has been caught out by the sudden sell-off, the events of February 27th could have lasting implications. The stockmarket has seen blacker Tuesdays. But this one may cast a long shadow.

　　這是市場易受突發(fā)不利事件影響的原因，也解釋了為什么借錢投資是危險的。如果一些銀行和大的對沖基金被這次突然拋售逮個正著，這次“2·27事件”的影響將會更加持久。盡管股市的歷史上不乏更加黑暗的“星期二”，但這一次投下了道長長的陰影。