华尔街-梦之队-的巨败之因（LTCM）案例分析（中/英版）ZT 投机市场中不存在百战百胜的法宝，任何分析方法与操作系统都有缺陷与误区。 美国长期资本管理公司的故事是最新最有说服力的证据。 一、LTCM营造的海市蜃楼 1.四大天王 美国长期资本管理公司（LTCM）总部设在离纽约市不远的格林威治，是一家主要从事定息债务工具套利活动的对冲基金。该基金创立于1994年，主要活跃于国际债券和外汇市场，利用私人客户的巨额投资和金融机构的大量贷款，专门从事金融市场炒作。它与量子基金、老虎基金、欧米伽基金一起被称为国际四大"对冲基金"。 2.梦幻组合 LTCM掌门人是梅里韦瑟（Meriwehter),被誉为能"点石成金"的华尔街债务套利之父。他聚集了华尔街一批证券交易的精英加盟：1997年诺贝尔经济学奖得主默顿（Robert Merton)和舒尔茨（Myron Schols),他们因期权定价公式荣获桂冠；前财政部副部长及联储副主席莫里斯（David Mullis)；前所罗门兄弟债券交易部主管罗森菲尔德（Rosenfeld)。这个精英团队内荟萃职业巨星、公关明星、学术巨人，真可称之为"梦幻组合 "。 3.骄人业绩 在1994--1997年间，LTCM业绩辉煌骄人。成立之初，资产净值为12.5亿美元，到1997年末，上升为48亿美元，净增长2.84倍。每年的投资回报率分别为：1994年28.5%、1995年42.8%、1996年40.8%、1997年17%。 4."致富秘笈" 长期资本管理公司以"不同市场证券间不合理价差生灭自然性"为基础，制定了"通过电脑精密计算，发现不正常市场价格差，资金杠杆放大，入市图利"的投资策略。 舒尔茨和默顿将金融市场历史交易资料，已有的市场理论、学术研究报告和市场信息有机结合在一起，形成了一套较完整的电脑数学自动投资模型。他们利用计算机处理大量历史数据，通过连续而精密的计算得到两种不同金融工具间的正常历史价格差，然后结合市场信息分析它们之间的最新价格差。如果两者出现偏差，并且该偏差正在放大，电脑立即建立起庞大的债券和衍生工具组合，大举套利入市投资；经过市场一段时间调节，放大的偏差会自动恢复到正常轨迹上，此时电脑指令平仓离场，获取偏差的差值。 5.法宝之瑕 但是不能忽视的是，这套电脑数学自动投资模型中也有一些致命之处：（1）模型假设前提和计算结果都是在历史统计基础上得出的，但历史统计永不可能完全涵盖未来现象。（2）LTCM投资策略是建立在投资组合中两种证券的价格波动的正相关的基础上。尽管它所持核心资产德国债券与意大利债券正相关性为大量历史统计数据所证明，但是历史数据的统计过程往往会忽略一些小概率事件，亦即上述两种债券的负相关性。 6.阴沟翻船 LTCM万万没有料到，俄罗斯金融风暴引发了全球的金融动荡，结果它所沽空的德国债券价格上涨，它所做多的意大利债券等证券价格下跌，它所期望的正相关变为负相关，结果两头亏损。它的电脑自动投资系统面对这种原本忽略不计的小概率事件，错误地不断放大金融衍生产品的运作规模。LTCM利用投资者那儿筹来的22亿美元作资本抵押，买入价值3250亿美元的证券，杠杆比率高达60倍。由此造成该公司的巨额亏损。 它从5月俄罗斯金融风暴到9月全面溃败，短短的150天资产净值下降90%，出现43亿美元巨额亏损，仅余5亿美元，已走到破产边缘。9月23日，美联储出面组织安排，以美林、摩根为首的15家国际性金融机构注资37.25亿美元购买了LTCM的90%股权，共同接管了该公司，从而避免了它倒闭的厄运。 二、LTCM兴衰的启示 1.投机市场中不可能出现神圣，任何人都会犯错误。长期资本管理公司，拥有世界上第一流的债券运作高手梅里韦瑟和罗森菲尔德，拥有世界上第一流的科研天才默顿和舒尔茨，拥有国际上第一流的公关融资人才莫里斯。但是这个"梦幻组合"中每个人物都应对LTCM的重挫负有责任。因此，我们股民不应迷信任何人，要有独立思考的能力。 2.投机市场中不存在致胜法宝，任何分析方法与操作系统都有缺陷与误区。LTCM曾经以为自己掌握了致富秘笈，在国际金融市场上连连得手，自信满满。可是偏偏出现了他们所忽视的小概率事件，使其造成巨额亏损已近破产。因此，我们股民运用任何方法或工具在证券市场上进行运作时，必须认识到它们有时会出错，会使你错失一些机会。如果它们出错只是小概率事件，正确是大概率事件（例如大于60%），而且比较适合你的个性，你就坚持使用它们，但也要注意下面的提示。 3.在投机市场上生存与发展，控制风险是永恒的主题。正因为在证券市场上任何人任何方法都可能出错，所以控制风险是我们股民应终生牢记在心的铁律。如果你所依赖的方法或工具，在出错时仅使你错失一些赚钱的机会，这并不要紧。如果它们出错时，有可能会令你伤筋动骨、全军覆没甚至负债累累，这样的风险就必须严格控制了。为了避免这些悲惨的结局在我们股民身上发生，首先我们不要透支炒股，其次我们不要借钱炒股，再次我们在高位炒股时要注意止蚀，最后我们不要盲目频繁炒作。 1994: Long-Term Capital Management is founded by John Meriwether and accepts investments from 80 investors who put up a minimum of $10 million each. The initial equity capitalisation of the firm is $1.3 billion. (The Washington Post, 27 September 1998) End of 1997: After two years of returns running close to 40%, the fund has some $7 billion under management and is achieving only a 27% return — comparable with the return on US equities that year. Meriwether returns about $2.7 billion of the fund's capital back to investors because "investment opportunities were not large and attractive enough" (The Washington Post, 27 September 1998). Early 1998: The portfolio under LTCM's control amounts to well over $100 billion, while net asset value stands at some $4 billion; its swaps position is valued at some $1.25 trillion notional, equal to 5% of the entire global market. It had become a major supplier of index volatility to investment banks, was active in mortgage-backed securities and was dabbling in emerging markets such as Russia (Risk, October 1998) 17 August 1998: Russia devalues the rouble and declares a moratorium on 281 billion roubles ($13.5 billion) of its Treasury debt. The result is a massive "flight to quality", with investors flooding out of any remotely risky market and into the most secure instruments within the already "risk-free" government bond market. Ultimately, this results in a liquidity crisis of enormous proportions, dealing a severe blow to LTCM's portfolio. 1 September 1998: LTCM's equity has dropped to $2.3 billion. John Meriwether circulates a letter which discloses the massive loss and offers the chance to invest in the fund "on special terms". Existing investors are told that they will not be allowed to withdraw more than 12% of their investment, and not until December. 22 September 1998: LTCM's equity has dropped to $600 million. The portfolio has not shrunk significantly, and so its leverage is even higher. Banks begin to doubt the fund's ability to meet its margin calls but cannot move to liquidate for fear that it will precipitate a crisis that will cause huge losses among the fund's counterparties and potentially lead to a systemic crisis. 23 September 98: Goldman Sachs, AIG and Warren Buffett offer to buy out LTCM's partners for $250 million, to inject $4 billion into the ailing fund and run it as part of Goldman's proprietary trading operation. The offer is not accepted. That afternoon, the Federal Reserve Bank of New York, acting to prevent a potential systemic meltdown, organises a rescue package under which a consortium of leading investment and commercial banks, including LTCM's major creditors, inject $3.5-billion into the fund and take over its management, in exchange for 90% of LTCM's equity. Fourth quarter 1998: The damage from LTCM's near-demise was widespread. Many banks take a substantial write-off as a result of losses on their investments. UBS takes a third-quarter charge of $700 million, Dresdner Bank AG a $145 million charge, and Credit Suisse $55 million. Additionally, UBS chairman Mathis Cabiallavetta and three top executives resign in the wake of the bank's losses (The Wall Street Journal Europe, 5 October 1998). Merrill Lynch's global head of risk and credit management likewise leaves the firm. April 1999: President Clinton publishes a study of the LTCM crisis and its implications for systemic risk in financial markets, entitled the President's Working Group on Financial Markets (Governance and Risk Control-Regulatory guidelines-president's working group) Lessons to be learned: Market values matter LTCM was perhaps the biggest disaster of its kind, but it was not the first. It had been preceded by a number of other cases of highly-leveraged quantitative firms that went under in similar circumstances. One of the earliest was Franklin Savings and Loan, a hedge fund dressed down as a savings & loan. Franklin's management had figured out that many of the riskier pieces of mortgage derivatives were undervalued because a) the market could not understand the risk on the risky pieces; and b) the market overvalued those pieces with well-behaved accounting results. Franklin decided it was willing to suffer volatile accounting results in exchange for good economics. More recently, the Granite funds, which specialised in mortgage-backed securities trading, suffered as the result of similar trading strategies. The funds took advantage of the fact that "toxic waste" (risky tranches) from the mortgage derivatives market were good economic value. However, when the Fed raised interest rates in February 1994, Wall Street firms rushed to liquidate mortgage-backed securities, often at huge discounts. Both of these firms claimed to have been hedged, but both went under when they were "margin-called". In Franklin's case, the caller was the Office of Thrift Supervision; in the Granite Fund's, the margin lenders. What is the common theme among Franklin, the Granite Funds and LTCM? All three depended on exploiting deviations in market value from fair value. And all three depended on "patient capital" -- shareholders and lenders who believed that what mattered was fair value and not market value. That is, these fund managers convinced their stakeholders that because the fair values were hedged, it didn't matter what happened to market values in the short run — they would converge to fair value over time. That was the reason for the "Long Term" part of LTCM's name. The problem with this logic is that capital is only as patient as its least patient provider. The fact is that lenders generally lose their patience precisely when the funds need them to keep it — in times of market crisis. As all three cases demonstrate, the lenders are the first to get nervous when an external shock hits. At that point, they begin to ask the fund manager for market valuations, not models-based fair valuations. This starts the fund along the downward spiral: illiquid securities are marked-to-market; margin calls are made; the illiquid securities must be sold; more margin calls are made, and so on. In general, shareholders may provide patient capital; but debt-holders do not. The lesson learned from these case studies spoils some of the supposed "free lunch" features of taking liquidity risk. These plays can indeed generate excellent risk-adjusted returns, but only if held for a long time. Unfortunately the only real source of capital that is patient enough to take fluctuations in market values, especially through crises, is equity capital. In other words, you can take liquidity bets, but you cannot leverage them much. Liquidity risk is itself a factor As pointed out in the analysis section of this article, LTCM fell victim to a flight to liquidity. This phenomenon is common enough in capital markets crises that it should be built into risk models, either by introducing a new risk factor — liquidity — or by including a flight to liquidity in the stress testing (see the following section for more detail on this). This could be accomplished crudely by classifying securities as either liquid or illiquid. Liquid securities are assigned a positive exposure to the liquidity factor; illiquid securities are assigned a negative exposure to the liquidity factor. The size of the factor movement (measured in terms of the movement of the spread between liquid and illiquid securities) can be estimated either statistically or heuristically (perhaps using the LTCM crisis as a "worst case" scenario). Using this approach, LTCM might have classified most of its long positions as illiquid and most of its short positions as liquid, thus having a notional exposure to the liquidity factor equal to twice its total balance sheet. A more refined model would account for a spectrum of possible liquidity across securities; at a minimum, however, the general concept of exposure to a liquidity risk factor should be incorporated in to any leveraged portfolio. Models must be stress-tested and combined with judgement www.6park.com Another key lesson to be learnt from the LTCM debacle is that even (or especially) the most sophisticated financial models are subject to model risk and parameter risk, and should therefore be stress-tested and tempered with judgement. While we are clearly privileged in exercising 20/20 hindsight, we can nonetheless think through the way in which judgement and stress-testing could have been used to mitigate, if not avoid, this disaster. According to the complex mathematical models used by LTCM, the positions were low risk. Judgement tells us that the key assumption that the models depended on was the high correlation between the long and short positions. Certainly, recent history suggested that correlations between corporate bonds of different credit quality would move together (a correlation of between 90-95% over a 2-year horizon). During LTCM's crisis, however, this correlation dropped to 80%. Stress-testing against this lower correlation might have led LTCM to assume less leverage in taking this bet. However, if LTCM had thought to stress test this correlation, given that it was such an important assumption, it would not even have had to make up a stress scenario. This correlation had dropped to 75% as recently as 1992 (Jorion, 1999). Simply including this stress scenario in the risk management of the fund might have led LTCM to assume less leverage in taking this bet. Financial institutions must aggregate exposures to common risk factors One of the other lessons to be learned by other financial institutions is that it is important to aggregate risk exposures across businesses. Many of the large dealer banks exposed to a Russian crisis across many different businesses only became aware of the commonality of these exposures after the LTCM crisis. For example, these banks owned Russian GKOs on their arbitrage desks, made commercial loans to Russian corporates in their lending businesses, and had indirect exposure to a Russian crisis through their prime brokerage lending to LTCM. A systematic risk management process should have discovered these common linkages ex ante and reported or reduced the risk concentration.
