文章大意如下：

一、全球市场的呈牛市格局，投资人过于轻率。

Margin of safety means the price paid for a stock or a bond should allow for human error, bad luck or, indeed,

many things going wrong at once.

The world is in the throes of a bull market in everything.

Rarely have creditors demanded so little insurance against default, even on the riskiest “junk” bonds.

And rarely have property prices around the world towered so high.

二、目前过高的资产价格有两点令人担心：基于过于量化宽松的货币政策，投资人为了追求高收益而忽视高风险

Asset-price booms are a source of cheer, but also anxiety. There are two immediate reasons to worry.

First, markets have been steadily rising against a backdrop of extraordinarily loose monetary policy.

If today’s asset prices have been propped up by central-bank largesse, its end could prompt a big correction.

Second, signs are appearing that fund managers, desperate for higher yields, are becoming increasingly incautious.

三、经济形式牛市格局很可能翻转，为此各国央行需要逐步加息以改变量化宽松的货币政策，同时银行和机构投资人需要明确自身的安全边界并准备好充足的资本金以抵档违约等风险。

Many hazards could derail the economy and financial markets. And when the next recession comes, policymakers have less fiscal and monetary ammunition to fight it than they had in previous downturns.

One option is for central bankers to raise rates more enthusiastically and less predictably,

to jolt financial markets and remind investors that the world is volatile.

And to minimise disruption, the reversal of quantitative easing should be stretched out.

But the main safety valve lies elsewhere, with banks and investors.

Banks must be able to withstand any reversal of today’s high asset prices and low defaults,

Which means raising bank capital in places where it is too low, especially the euro zone.

They and regulators should take a leaf out of “The intelligent Investor”,

and make sure that they have a margin of safety.