????投資往往為被描述為這樣一個(gè)過(guò)程，現(xiàn)在投入一些錢,，希望未來(lái)能收回更多的錢。在伯克希爾哈撒韋（Berkshire Hathaway）,，我們采用更高的標(biāo)準(zhǔn),，將投資定義為“現(xiàn)在將購(gòu)買力讓渡給他人，合理期待未來(lái)支付明義收益稅率后,，仍能獲得更高的購(gòu)買力”,。簡(jiǎn)言之,，投資就是放棄現(xiàn)在的消費(fèi)，以便將來(lái)有能力消費(fèi)更多,。

????從我們的定義可以得出一個(gè)重要結(jié)論：衡量投資風(fēng)險(xiǎn)高低的指標(biāo)不應(yīng)是貝塔值（一個(gè)基于波動(dòng)率的華爾街術(shù)語(yǔ)，常用于衡量風(fēng)險(xiǎn)）,，而是持有期滿后投資人出現(xiàn)購(gòu)買力損失的（合理）概率,。資產(chǎn)價(jià)格可能大幅波動(dòng)，但只要有理由肯定投資期滿后它們帶來(lái)的購(gòu)買力能得到提升,，這項(xiàng)投資就沒(méi)有風(fēng)險(xiǎn),。稍后我們還會(huì)看到,，價(jià)格沒(méi)有波動(dòng)的資產(chǎn)也可能充滿風(fēng)險(xiǎn)。

????投資選擇林林總總,，但大體可分為三類,，理解每一類的特點(diǎn)很重要。下面,，我們將展開詳細(xì)的分析,。

????市場(chǎng)上以特定貨幣結(jié)算的投資包括貨幣市場(chǎng)基金、債券,、按揭、銀行存款和其他工具,。大多數(shù)此類投資都被視為“安全”,，但事實(shí)上卻是可能屬于最危險(xiǎn)的資產(chǎn)。它們的貝塔值可能是零,，但風(fēng)險(xiǎn)巨大,。

????上個(gè)世紀(jì),，這類投資工具摧毀了很多國(guó)家投資者的購(gòu)買力，盡管投資者一直能夠按時(shí)收到支付的本息,。而且,，這樣的糟糕結(jié)果將來(lái)還會(huì)不斷重現(xiàn)。政府決定貨幣的最終價(jià)值,，而系統(tǒng)性力量有時(shí)會(huì)推動(dòng)它們制定導(dǎo)致通脹的政策,。這些政策一不留神就會(huì)失控,。

????Investing is often described as the process of laying out money now in the expectation of receiving more money in the future. At Berkshire Hathaway (BRKA) we take a more demanding approach, defining investing as the transfer to others of purchasing power now with the reasoned expectation of receiving more purchasing power -- after taxes have been paid on nominal gains -- in the future. More succinctly, investing is forgoing consumption now in order to have the ability to consume more at a later date.

????From our definition there flows an important corollary: 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. Assets can fluctuate greatly in price and not be risky as long as they are reasonably certain to deliver increased purchasing power over their holding period. And as we will see, a nonfluctuating asset can be laden with risk.

????Investment possibilities are both many and varied. There are three major categories, however, and it's important to understand the characteristics of each. So let's survey the field.

????Investments that are denominated in a given currency include money-market funds, bonds, mortgages, bank deposits, and other instruments. Most of these currency-based investments are thought of as "safe." In truth they are among the most dangerous of assets. Their beta may be zero, but their risk is huge.

????Over the past century these instruments have destroyed the purchasing power of investors in many countries, even as these holders continued to receive timely payments of interest and principal. This ugly result, moreover, will forever recur. Governments determine the ultimate value of money, and systemic forces will sometimes cause them to gravitate to policies that produce inflation. From time to time such policies spin out of control.