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发表于 2009-7-25 10:07 AM
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本帖最后由 seabiscuit 于 2009-7-25 11:15 编辑
我这次失败的经验总结, 和Duoji分享一下。这次我在the market 连涨好多天后加重仓short,这是致命的错误,后果是严重的。 而当时我为什么made such a bad decision after long time thinking?
现在,仔细回想了一下当时的 my decision making process. 发现自己doubled down 最重要的理由就是Naz 连涨超过N 天的机会很少,我查了historical data, 发现occurrence 非常rare, 属于非常小的概率事件。 炒股就是往概率大的地方赌, 我当时问自己为什么不敢赌, 既然odds in favor of me?
其实, 我的reasoning 是有serious flaws. 这次我们是已经观察到,Naz 连涨7 天。 我应该考虑的是 given this happens, what is the probability that Naz would continue to move up? This is a conditional probability which I should have considered for my decision making, instead of using the unconditional probability (i.e., the probability that Naz has been up for more than 7 days). 当我看historical data 时, 我应该只看那些已经连涨7 天的cases, 再看第八天what will happen?我就会发现情况是非常的不利。我们并没有any edge.
所以下次这种情况再发生时,应该把自己的仓位和已有的loss 放一边,用心去体会市场的信号, 如果感觉市场仍然很强, 应马上止损, 不要wishful thinking that some sudden event would disrupt the rally。 甚至, why not enter the market with protection, 如果市场意志坚决? |
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