回复@zhulinhao1: 看巴菲特过去的投资，可以看出他其实是很保守的。段永平也是非常保守的，腾讯拼多多他看了这么多年，谈了这么多年，也认识这两家公司的高管，最后也就放了小个位数的仓位，即使是苹果，他放进去的仓位（算上步步高oppo、vivo的股权）也没大家想象中那么高。//@zhulinhao1:回复@张浩_:巴菲特最大比例的持股是partnership时期的$美国运通(AXP)$ ，为了买美国运通巴菲特直接修改了他在设立partnership时的ground rule：
We diversify substantially less than most investment operations.We might invest up to 40% of our net worth in a single security under conditions coupling an extremely high probability that our facts and reasoning are correct with a very low probability that anything could drastically change the underlying value of the investment.
把partnership的单一股票投资额度上修到了40%，当时实际持股大约占整个partnership的35%左右，巴菲特说这种极限投资发生在“我们的对事实的认知和逻辑有极大可能性是正确的，且无论任何事情发生都很难大幅改变这项投资的价值”的情况下。