VanTharp的三种资产计算方法

Discussion in 'Risk and Uncertainty' started by Toby, Nov 18, 2009.

  1. 资产模型类型有三种:
    1. core equity method 核心资产计算法

    1)核心资产 = 初始资产 - 每单开仓时占用的资产。
    2)每当平仓时,要重新计算核心资产。
    3)新开仓位要建立在当前核心资产基础的函数上。

    举例: 初始帐户现金50000, 每次开仓时以核心资产的10%开仓。

    第一单为5000,开仓后, 这时的核心资产为45000,只要此单没平仓,不管浮动盈利还是浮动亏损, 核心资产不变,一直是45000.

    第二单,第一单还未平仓时开第二单, SIZE = 45000×10%=4500, 这时的核心资产变为40500=50000-5000(第一单)-4500(第二单)。

    第三单,在前两单未平仓情况下,第三单SIZE=当前核心资*10%=40500*10%=4050. 这时的核心资产变为36450.


    2. total equity method 总资产计算法 (采用最多的方法)
    总资产 = 现金+未平仓的当前价值


    3. reduced total equity method 递减资产计算法 (前两种方法的综合)
    递减资产 = 核心资产+当前已被锁定利润的未平仓的浮盈

    举例:当前50000元的帐户,
    开仓5000后,资产变为45000,
    产生了2000的利润后,资产变以47000,
    又回吐了1000的利润后,资产仍为47000,资产只会增大,不会减小。原因是用跟踪止损把利润锁定了。
     
  2. 我采用的是trade初的equities为初始资金E1。在整个trade过程,不管加仓,减仓,计算都按照E1来计算。风险都是以E1为基础的。待关闭trade的最后一个头寸,那么E1将被重新计算。

    好像和上面3种都不一样。
     
  3. ranzo, 我认为你的方法更合理一些.
     
  4. 这个似乎有误,产生了2000的利润,资产变成47000,我的理解是这2000的利润已经锁定了,也就是你说的跟踪止损锁定利润。那么如果又回吐1000的利润的话,按道理应该已经离场了才对,因为肯定已触发跟踪止损的止损线了。

    我认为正确的描述应该是:
    产生了4000的利润,其中2000的利润是被跟踪止损锁定的,于是资产变为47000。如果利润回吐1000,变成3000,但还未触及跟踪止损线,所以资产还是47000:)
     
  5. 如果只有这三种让我选择,我肯定选第一种,因为第一种对风险的控制最好。
    第二种其实是放大了风险,第三种看似没有放大风险,但如果碰到黑天鹅事件,你的头寸数量可能已过大,这种情况存在潜在放大的风险。
     
  6. VanTharp博士的这些想法令人耳目一新。不知道以初始资产减去冒险金额作为核心资本如何?比如,初始资产50000,投资准备损失2000,占用资金10000,那么以48000作为核心资本会怎么样呢?
     
  7. 可能我翻译的不好,下面是第三种的原文,欢迎探讨。
    The reduced total equity method is a combination of the
    first two methods. It is like the core equity method in that the
    exposure allocated when you open a position is subtracted from
    the starting equity. However, it is different in that you also add
    back in any profit or reduced risk that you will receive when
    you move a stop in your favor. Thus, reduced total equity is
    equivalent to your core equity plus the profit of any open
    positions that are locked in with a stop or the reduction in
    risk that occurs when you raise your stop.5


    Here’s an example of reduced total equity. Suppose you
    have a $50,000 investment account. You open a position with a
    $5,000 position sizing allocation. Thus, your core equity (and
    reduced total equity) is now $45,000. Now suppose the
    underlying position moves up in value and you have a trailing
    stop. Soon you only have $3,000 in risk because of your new
    stop. As a result, your reduced total equity today is $50,000
    minus your new risk exposure of $3,000, or $47,000.


    The next day, the value drops by $1,000. Your reduced
    total equity is still $47,000 since the risk to which you are
    exposed if you get stopped out is still $47,000. It changes only
    when your stop changes to reduce your risk, lock in more
    profit, or close out a position.