而为了使自己的投资组合保值，每年常常需要用资金的百分之五到十购买期权，来抵御指数下百分之十所带来的风险。换句话说，游戏还没开始，自己就先损失了一部分。而且期权还有时限，通常为三个月，过了期限还得再买一份

Last year I told you that Berkshire had 62 derivative contracts that I manage. (We also have a few
left in the General Re runoff book.) Today, we have 94 of these, and they fall into two categories.
First, we have written 54 contracts that require us to make payments if certain bonds that are
included in various high-yield indices default. These contracts expire at various times from 2009 to 2013.
At yearend we had received $3.2 billion in premiums on these contracts; had paid $472 million in losses;
and in the worst case (though it is extremely unlikely to occur) could be required to pay an additional $4.7
billion.
We are certain to make many more payments. But I believe that on premium revenues alone,
these contracts will prove profitable, leaving aside what we can earn on the large sums we hold. Our
yearend liability for this exposure was recorded at $1.8 billion and is included in “Derivative Contract
Liabilities” on our balance sheet.
The second category of contracts involves various put options we have sold on four stock indices
(the S&P 500 plus three foreign indices). These puts had original terms of either 15 or 20 years and were
struck at the market. We have received premiums of $4.5 billion, and we recorded a liability at yearend of
$4.6 billion. The puts in these contracts are exercisable only at their expiration dates, which occur between
2019 and 2027, and Berkshire will then need to make a payment only if the index in question is quoted at a
level below that existing on the day that the put was written. Again, I believe these contracts, in aggregate,
will be profitable and that we will, in addition, receive substantial income from our investment of the
premiums we hold during the 15- or 20-year period.
Two aspects of our derivative contracts are particularly important. First, in all cases we hold the
money, which means that we have no counterparty risk.
Second, accounting rules for our derivative contracts differ from those applying to our investment
portfolio. In that portfolio, changes in value are applied to the net worth shown on Berkshire’s balance
sheet, but do not affect earnings unless we sell (or write down) a holding. Changes in the value of a
derivative contract, however, must be applied each quarter to earnings.
Thus, our derivative positions will sometimes cause large swings in reported earnings, even
though Charlie and I might believe the intrinsic value of these positions has changed little. He and I will
not be bothered by these swings – even though they could easily amount to $1 billion or more in a quarter –
and we hope you won’t be either. You will recall that in our catastrophe insurance business, we are always
ready to trade increased volatility in reported earnings in the short run for greater gains in net worth in the
long run. That is our philosophy in derivatives as well.