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VAR (Value at Risk) 与个股投资
定义:
In finance, the term "VaR" refers to Value at Risk, a statistical measure used to quantify the potential loss of an investment portfolio or firm over a specific time period with a given probability. It answers the question: "What is the maximum potential loss, at a specific confidence level, over a defined timeframe?". For instance, a portfolio with a one-day VaR of $1 million at a 95% confidence level means there's a 5% chance the loss will exceed $1 million.
延伸: 个股购买时,影响未来一段时间(比如一年)股价因数大致有:大盘变化(beta体现在这里),股票盈利变化(比购买时变好或者变差),其它影响股价的因素(比如EV credit),等等。
VAR: 如果按正常估计的概率得到的VAR比较小,同时预期盈利高,(还可以加上div), 那么是一个好的购买。相反,如果这个数值比较大,或者拥有过程中变大,那么就要小心了。
Loss 概率体现在购买者对风险的忍耐度。买lottery 和买T bill 是两个极端。买小药股和买WMT也是非常好的对比。
有空瞎算算,挺有意思的。
https://www.investopedia.com/terms/v/var.asp