The next financial crisis will be played out in indexes and exchange traded funds. That is inevitable given the huge share that ETFs now take of investor fund flows, and their popularity as hedge fund trading vehicles.

下一场金融危机将在指数和交易所交易基金(ETF)领域上演。这是不可避免的，因为目前它们在投资者的资金流动中占有巨大份额，同时它们作为对冲基金交易工具很受欢迎。

What is less clear, and deeply controversial, is whether the structure of ETFs will itself contribute to the next crisis, or even cause it. Regulators, worried by past incidents when untested financial innovations helped exacerbate financial crises, are worried that it could.

不太清楚、争议程度很高的是，ETF的结构本身是否将对下一场危机起到推波助澜的作用、甚至引发危机。监管机构担心，这是有可能的：未经过考验的金融创新在过去就曾加剧了金融危机。

ETF providers indignantly counter that they make the market more liquid, and less prone to sudden stops. Indeed, they complain that well-intentioned regulations exacerbate a problem they were meant to cure.

ETF提供商愤慨地反驳称，他们增加了市场流动性，降低了市场突然停摆的可能性。他们抱怨称，实际上，是那些出于好意的监管规定加剧了它们本应解决的问题。

The scale of the ETF industry is not in question. They now hold more than $3tn in assets. But this raises the question of whether they have come to lead the market rather than follow it. This operates at two levels. First, there is a concern that the power of the indexes distorts markets over time, and second, there is the possibility that the structure of ETFs and index funds worsens market shocks when they happen.

ETF行业的规模不是问题。目前ETF掌管的资产规模高于3万亿美元。但这引出了这样一个问题，即ETF是否已开始引领市场、而非跟随市场。质疑来自两个层面。首先，人们担心，指数的力量会随着时间推移扭曲市场。其次，在市场发生危机时，ETF和指数基金的结构可能会加剧危机程度。

Indexes’ influence spreads to virtually all institutionally managed funds. Benchmarking by the consultants on whom institutions rely when choosing fund managers is so widespread, that active managers have no choice but to watch the index they are compared to very closely, and are obliged to follow any major changes in its composition.

指数影响到几乎所有机构管理基金。机构选择基金经理时依赖顾问的意见，而顾问对基金经理进行标杆比较(Benchmarking)的做法十分普遍，结果主动性基金经理只能非常密切地跟踪被拿来与自己比较的指数，并且被迫跟随该指数成分股的任何重大变化调整自己的投资组合。

Examples are easy to come by. When the Russell indices — highly popular among US fund managers — are updated each year, they often drive the heaviest trading of the year. In June this year, Chinese A-shares peaked and began to fall shortly after MSCI, the most important index provider for emerging markets, decided to delay including them in its flagship index. This came as a surprise. Showing the importance of indexers, Chinese authorities had lobbied hard for inclusion, as this would have driven capital into the A-shares market. Many investors at the time said that the subsequent sell-off could in part be attributed to the knock to confidence that came with MSCI’s decision.

例子很容易找到。当在美国基金经理中特别受欢迎的罗素(Russell)指数每年更新成分股时，经常会带出年内最密集的交易。去年6月，当对新兴市场而言最重要的指数提供商MSCI明晟决定暂缓把中国A股纳入其旗舰指数之后，中国A股很快就见顶并开始下跌。这当时让人感到意外。说明了指数提供商重要性的是，中国当局之前一直努力游说，希望MSCI明晟同意纳入A股，因为那将推动资金流入A股市场。当时，许多投资者表示，随后的抛售可能部分是因为MSCI明晟的决定导致市场信心受损。

Indexers do their best to limit their impact on the market. Russell makes its methodology very public, so investors can see weeks in advance what changes are likely to its indices. MSCI conducts public consultations.

指数提供商尽量降低他们对市场的影响。罗素完全公开了其指数编制方法，所以投资者可以提前数周看到其指数可能发生的变化。

But while indexing and benchmarking remain so prevalent, the problem of overpowerful indexes seems impossible to avoid. It can merely be mitigated. For passive investors, rules for indexes must remain as clear as possible. For active managers, the solution may be to change benchmarking. Rather than looking at past performance, which does not predict the future, consultants could look at investors’ past behaviour, or rate them on their degree of style discipline. If clients show that they are more interested in highly concentrated funds taking contrarian positions, and not in funds that merely shadow an index, then the industry would adjust to meet the demand, and the systemic problems caused by indexes should reduce.

但是，在指数编制和标杆比较仍很盛行之际，指数过于强大的问题似乎难以避免，只能尽量减轻。对于被动投资者而言，指数编制规则必须保持尽可能透明。对于主动型经理而言，解决办法或许是改变标杆比较方法。顾问们可以不再考察基金经理的过往业绩（过去的业绩不代表未来），而是考察投资者的过往行为，也就是根据其风格的一贯性为其打分。如果客户表明，他们更感兴趣的是与市场反向持仓、高度有的放矢的基金，而不是仅仅复制指数的基金，那么行业将进行调整以满足此需求，指数引发的系统性问题也就应该会减轻。

Then there is the issue of market structure. Two incidents in 2015 raised concern. First, there was August 24, when US share prices gapped downwards at the opening in New York, and ETF prices were not available for a while. Second, in December, a gradual sell-off in high-yield bonds turned into a rout for ETFs holding high-yield bonds.

接着还有市场结构的问题。2015年的两起事件引发了担忧。第一件发生在8月24日，纽约股市开盘时，股价跳空下跌，一段时间内ETF的价格无法生成。第二件发生在12月，一场逐渐升级的高收益债券抛售潮导致持有高收益债券的ETF大幅下跌。

Was this due to liquidity mismatches? It is a fair question. ETFs only offer prices throughout the trading day because market makers trade to ensure that there is no gap between the market price and the underlying price of the securities in the index they track, so this has to be a risk — especially when, as in the case of high-yield bonds, the underlying security is fundamentally less liquid.

这种局面是流动性错配导致的吗？这是一个合情合理的问题。ETF仅在整个交易日内提供价格，因为做市商进行交易，以确保他们所跟踪指数中的证券的市场价格和基础价格之间没有落差，那么这必然造成一种风险，尤其是当标的证券根本就流动性不足的时候（就像是高收益债券的情况那样）。

There are two theories. One, held by the industry, is that the problems were driven if anything by regulations. Mandatory trading pauses following the 2010 “flash crash” made it harder for ETF managers to get a handle on the underlying price of their securities, and created problems. The other theory: there is indeed a mismatch.

对此存在两种观点。一个是行业的观点，认为问题是由监管导致的（如果说存在原因的话）。在2010年的“闪电崩盘”(flash crash)之后，交易被强行暂停，导致ETF经理更难掌握其证券的基础价格，引发了问题。另一种观点认为，流动性错配确实存在。

Debate is healthy. The echoes of credit derivatives, which in 2008 helped to turn a serious housing downturn into a near-collapse of the world financial system, are clear enough. Without a major market disruption — and 2015’s turbulence barely ranks compared with the events of 2008 — it is hard to test whether new financial instruments will work as intended when under stress. Better for everyone, including ETF providers, to err on the side of caution.

辩论是有益的。2008年，一场严重的住房市场下跌之所以差点儿导致世界金融系统崩溃，就是因为信贷衍生品的推波助澜。信贷衍生品敲响的警钟仍清晰可闻。如果不发生一次重大的市场紊乱（2015年的动荡跟2008年的市况相比几乎算不上动荡）,我们很难验证新的金融工具在压力之下能否正常运转。对于包括ETF提供商在内的所有人而言，宁愿失之过于谨慎，也不要掉以轻心。