什么是投资风险？
看似很简单的一个问题。从纯学术角度，“风险”是用价格波动的幅度来衡量的。所以对于很多人来说，价格波动幅度基本等同与投资风险。波动越大，风险越高。反之亦然。常用的beta， 标准差，夏普比率等等都基于这个假设。但波动真的就是风险吗？
巴菲特并不这么看。
价格的波动对于他来说是market performance, 而他真正关心的是business performance。 他曾经说：
"We look to business performance, not market performance. If we are correct in expectations regarding the business, the market will eventually follow along."
（我们看的是公司本身的表现，而不是股价的表现。 如果我们在判断公司发展方面的判断是对的，那股市最终会顺从。）
“In business schools, volatility is almost universally used as a proxy for risk. Though this pedagogic assumption makes for easy teaching, it is dead wrong: Volatility is far from synonymous with risk. Popular formulas that equate the two terms lead students, investors and CEO’s astray."
（商业学院总是把价格浮动看作是风险的代名词。 虽然这样的假设教起来比较容易，却极其错误。波动和风险远不是一回事。把这两个概念混淆让学生，投资人和CEO都很受误导。）
对于巴菲特来说， 失去本金购买力的可能性才是真正的风险：
“The riskiness of an investment is not measured by beta (a Wall Street term encompassing volatility and often used in measuring risk) but rather by the probability – the reasoned probability – of that investment causing its owner a loss of purchasing-power over his contemplated holding period."
（衡量投资风险的标准不是beta, 而是概率， 基于理性分析的概率，让投资人在投资期限里失去本金购买力的可能性。）
那巴菲特是如何将这种概率降到最低的呢？
只投资那些在自己理解范畴之内的公司
“Different people understand different businesses. And the important thing is to know which ones you do understand and when you’re operating within what I call your “circle of competence.”
（不同的人对各种生意的理解程度不一样。 关键是要知道你擅长理解的东西是什么，你是不是在你的能力范围之内进行投资）
"Risk comes from not knowing what you're doing."
（如果你不知道自己在做什么，这才是风险。）
“We will never buy anything we don’t think we understand. And our definition of understanding is thinking that we have a reasonable probability of being able to assess where the business will be in 10 years.”
（我们不理解的东西，我们不会去买。 我们对“理解”的定义是，能够大概率地判断一个投资在10年后将会是个什么状况。）
长时间持有
“We do define risk as the possibility of harm or injury. And in that respect we think it’s inextricably wound up in your time horizon for holding an asset. I mean, if your risk is that if you intend to buy XYZ Corporation at 11:30 this morning and sell it out before the close today, in our view that is a very risky transaction. Because we think 50 percent of the time you’re going to suffer some harm or injury. If you have a time horizon on a business, we think the risk of buying something like Coca-Cola at the price we bought it at a few years ago is essentially so close to nil, in terms of our perspective holding period. But if you asked me the risk of buying Coca-Cola this morning and you’re going to sell it tomorrow morning, I say that is a very risky transaction.”
（我们认为风险是造成伤害和损失的概率。从这个角度说，风险和你的投资期限有很大关系。比如说，你打算在今天11:30买XYZ的股票，然后在今天收市前再卖掉，那风险肯定很大。因为你有约50%的可能性会遭受损失。而相对于我们的投资期限，我们在几年前以当时的价格买的可口可乐，几乎没有任何风险。如果你问我今天上午买可口可乐，然后明天上午卖掉的风险，那就不一样了，非常大。）
“Our favorable holding period is forever.”
(我们最喜欢的投资期限是永远。）
具有可以持续的竞争优势
“The first filter we probably put it through is whether we think — and we know instantly — whether it’s a business we’re going to understand, and whether it’s a business that — if it passes through that, it’s whether a company can have a sustainable edge.”
（我们的第一个筛选条件是，这个商业模式我们是不是可以理解，如果通过了这个标准，然后就是这个公司有没有可持续的竞争优势。）
卓越的管理层
“We have some filters in regard to people, too.”
（我们对人员也有筛选条件。）
"We do not wish to join with managers who lack admirable qualities, no matter how attractive the prospects of their business."
（我们不希望和那些欠缺令人倾佩品质的人合作，不管这些人的生意做地多么好。）
具有良好的历史业绩
“If it’s got a lousy past but bright future we’ll miss it.”
（如果你历史业绩暗淡，但前途一片光明，我们会放弃。）
"Start ups are not our game."
（新创公司不是我们的投资对象。）
“Charlie and I haven’t bought an IPO since 1955.”
（查理和我从1955年起就没有买过一个IPO。）
"We don’t play big trends. We don’t think about demographic trends or anything of the sort.... Big trends, they just don’t mean that much. There’s too much money to be made from year to year to think about things that take decades to manifest themselves."
（我们不玩大趋势的东西。 不去考虑人口变化等等这类因素。对我们来说没有什么意义。 眼前就有很多可以赚钱的机会，干嘛去看那些要等好多年才可以实现的东西。）
足够的安全边际
"We insist on a margin of safety in our purchase price. If we calculate the value of a common stock to be only slightly higher than it's price, we're not interested in buying. We believe this margin of safety principle, emphasized by Ben Graham, to be the cornerstone of investment success"
（购买价格要就有足够的安全边际。如果我们计算的股价只是比当前的价格高出一点点，那我们不感兴趣。 我们相信格莱姆强调的安全边际原则，它是我们投资成功的关键因素。）
避开最坏可能，不承担不必要的风险
“We think in terms of not exposing ourselves to any mistakes that could really hurt our ability to play tomorrow. And so we are always thinking about, you know, worst-case situations … we have to think about whether we’re doing anything really big that could have really terrible consequences.”
（我们总是尽力避开那些损害我们未来投资能力的错误，所以，总是在琢磨最坏可能是什么。我们当前的决定是不是可能造成非常恶略的后果。）
“I put heavy weight on certainty .. if you do that, the whole idea of a risk factor doesn’t make any sense to me. You don’t do it where you take a significant risk. But it’s not risky to buy securities at a fraction of what they are worth.”
（我对确定性非常看重。如果你从这个角度来思考，那么风险因素这个概念意义就不大了。如果风险大，就不做好了。用其真正价值的一小部分的价格来购买证券，没什么风险。）
“I would rather be, you know, a hundred times too cautious than 1 percent too incautious, and that will continue as long as I’m around.”
（我宁愿100倍地太过谨慎，也不愿意1%地不够谨慎。 只要我在，一直都会这样。）
总结：
在金融市场上赚钱的方法不只一种。 对于巴菲特，为了高回报而去承受高风险是很荒谬的事情。他只关注那些他有能力理解和判断未来趋势的投资，并且长期持有。如果这些投资有良好的历史业绩，优秀的管理人，可持续的竞争优势，而且价格有足够的吸引力，那么对于巴菲特来说，这些投资几乎是没有什么风险的。
在下次你筛选投资机会的时候，不妨重温一下上面这些巴老的教诲。
“The best way to minimize risk is to think”
