解讀新一輪全球範圍內的資產拋售

Last week’s global sell-off, the worst since January, had all the features that make such market events both frightening and exciting for investors. It serves as a reminder to policy makers of the latent threats to financial stability, and the implication this carries for growth and jobs. It also provides insights for the more bumpy road that lies ahead.

最近一輪全球資產拋售是今年1月以來最爲嚴重的，擁有既讓投資者感到恐慌、又讓他們感到興奮的市場事件的所有特徵。它讓政策制定者感到了金融穩定的潛在威脅，以及這種威脅可能給經濟增長和就業帶來的影響。它還讓人們看到，未來的道路更加崎嶇不平。

The sell-off was sharp, sudden and generalised. In just a few days the downturn erased the year-to-date gains for major US equity indices, with virtually every segment – both large and small – experiencing significant losses. To add insult to injury, conventional correlations among asset classes broke down as the spillover of the equity market correction spread beyond corporate credit. Commodities also sold off, as did the safest of all havens, German and US government bonds. Well-diversified asset allocations did little to mitigate portfolio risks.

此次拋售是劇烈、突然和全面的。在短短几天時間裏，美國主要股指的下跌就抹平了今年以來的漲幅，幾乎所有板塊（無論是大還是小）都出現了大幅下挫。雪上加霜的是，隨着股市調整的溢出效應蔓延至企業信貸以外，不同資產類別的傳統關聯也被打破。大宗商品也遭到拋售，最安全的避險資產德國國債和美國國債同樣如此。多樣化投資無助於減輕投資組合風險。

Rather than being driven by a single factor, the correction reflected the cumulative impact of multiple causes that markets could no longer shrug off given high valuations and unbalanced investor positioning. They covered geopolitical, financial, economic and policy factors.

考慮到市場的高估值和投資者頭寸失衡，此次調整反映出市場不再無視多種因素——而非僅僅受到單一因素的推動——累積的影響。這些因素涵蓋地緣政治、金融、經濟和政策幾個方面。

Geopolitical tensions

地緣政治緊張局勢

On the geopolitical front, markets could no longer ignore mounting tensions that risk disrupting global growth, trade and energy. These include the escalating violence in Ukraine, along with the widening Moscow-west divide that it fuels; civilian deaths in Gaza, and the risk of future radicalisation; the deteriorating rule of law in Iraq and Libya; and the continuing fragmentation of Syria.

市場不再忽視日益加劇的地緣政治緊張局勢，後者可能影響全球增長、貿易和能源。這些緊張局勢包括烏克蘭日益惡化的暴力衝突，再加上由此引發的莫斯科與西方分歧加劇；加沙平民死亡和未來極端化的風險；伊拉克和利比亞法治日益惡化，以及敘利亞持續分裂。

On the financial front, Argentina’s debt default highlighted the extent to which today’s sovereign debt regimes are sensitive to the disruptive influence of intransigent minority holdout creditors facing entrenched governments.

在金融方面，阿根廷債務違約突顯出，在政府根基穩固的情況下，當前主權債務體制對拒不妥協的少數不合作債權人所帶來的破壞性影響是多麼的敏感。

Meanwhile, economic data out of Europe accentuated concerns about the region’s weak recovery. And, on the policy side, more hawkish statements from a growing number of US Federal Reserve officials raised questions about the central bank’s resolve to continue its steadfast support for markets and the economy.

與此同時，歐洲發佈的經濟數據加劇了人們對該地區經濟復甦疲弱的擔憂。從政策方面來說，越來越多的美聯儲(Fed)官員發表了更具有鷹派色彩的聲明，這讓人對美聯儲繼續毫不動搖地支持市場和經濟的決心產生懷疑。

Having already rallied beyond levels easily validated by underlying fundamentals, markets were no longer able to ignore the compounding risks of such a set of factors. The result was a generalised retreat with virtually no place to shelter other than cash and true cash equivalents; or, at least, no shelters readily accessible to many investors. (Professionals could protect their portfolios using both short positioning and insurance, via credit default swaps, though many loathe the costs and risks these entail.)

市場已經上漲至基本面所能支持的水平以上，它們不再能夠忽視這一系列因素累積的風險。結果是除了現金和真正的現金等價物以外，幾乎所有資產類別都無法抵禦市場的全面下挫。或者最起碼來說，許多投資者都無法輕易地避險（專業人士可能利用空頭頭寸和通過信用違約互換(CDS)保險機制來保護他們的投資組合，儘管許多人厭惡這些工具必然帶來的成本和風險）。

The breakdown in traditional correlations among different asset classes renders such a sell-off even more unsettling, potentially triggering investor reactions that compound the initial adverse market moves. Over the years I have found two tools particularly helpful for understanding these reactions.

不同資產類別之間的傳統關聯被打破，導致此類拋售更令人擔憂，有可能讓投資者做出加劇最初不利的市場走勢的反應。多年來，我發現兩個工具尤其有助於理解這些反應。

Behavioural insights

行爲金融和檸檬理論

The first comes from behavioural finance, which reminds us that certain characteristics, such as natural herding tendencies and destabilised framing mindsets, encourage subsequent market overshoots. Second, the “Markets for Lemon” hypothesis formulated by George Ackelof in 1970 explains why information asymmetry and signalling problems expose both strong and weak securities to large market sell-offs notwithstanding quite large differences in their fundamentals.

首先是行爲金融，它提醒我們，某些特徵，比如天生的羊羣傾向和破壞穩定的框架思維，鼓勵了隨後的市場過度反應。其次，喬治•阿克洛夫(George Ackelof)在1970年提出的“檸檬市場”假說解釋了爲何信息不對稱和信息傳遞問題讓證券無論優劣都受到市場大幅拋售的影響，儘管這些證券的基本面存在巨大的差異。

These insights are likely to prove particularly relevant given the extent to which the prior period of volatility repression by central banks has induced investors to leverage positions and, in the process, compress a host of risk premia (including credit, default, equity liquidity and volatility). At the same time there is little appetite among broker-dealers to warehouse risk. Indeed, rather than serving as a shock absorber, their current approach to balance sheet management initially amplifies market overshoots.

鑑於各國央行前期大力抑制波動性，從而誘使投資者舉債增加頭寸，並在此過程中壓縮一系列風險溢價水平（包括信貸、違約、股票流動性和波動性），這些觀點可能尤其具有重要意義。與此同時，經紀自營商幾乎沒有承擔風險的想法。實際上，它們當前的資產負債表管理方式最初放大了市場過度反應，而沒有對衝擊起到緩和的作用。

All this should also worry western policy makers. Because of political problems that preclude a comprehensive policy approach, they have been forced to rely on asset markets as the conduit for attaining their growth and employment objectives. As such, the higher the probability of generalised market sell-offs, the greater the risks to financial stability and the wellbeing of Main Street.

所有這些也應該讓西方政策制定者感到擔心。由於政治上的問題，他們無法實施全面的政策手段，只能被迫把資產市場作爲實現增長和就業目標的通道。就此而言，市場全面拋售的可能性越高，金融穩定性和普通民衆福利面臨的風險就越大。

Yet technical sell-offs also offer opportunities for those able and willing to underwrite high price volatility. Because they initially hit both strong and weak assets, investors can pick up good assets at overly depressed prices. The hope is that such investors can, and will, act in enough numbers and on a sufficiently timely basis to avert economic damage from generalised market downturns.

然而技術性拋售也爲那些有能力、也願意承擔較高的價格波動性的人提供了機遇。因爲它們最初對所有資產（無論強弱）都造成衝擊，投資者可以以極爲便宜的價格購得好的資產。希望在於，能夠而且將會採取行動的此類投資者足夠多，而且也足夠及時，能夠避免市場全面下跌對經濟造成破壞。