本帖最后由 TXK 于 2009-8-13 15:13 编辑
5# 蓉儿
蓉儿, Drys可以长期持有吗?目标是多少?我现在想找点好股长期布仓. 大约持有1-2年以上.如果震荡, 买SSO好不好?总觉得比较安全.或者说spx?
kitten3 发表于 2009-8-13 14:21 
如果想长期持有(1-2年以上),就不要碰leverage ETFs, 如sso(200%x),MWN(300%x)。不论你赌哪面,长期下来你都会输的很惨。数学证明如下。所以想buy and hold,或买大盘股,DIA,SPY,QQQQ等; 或买有潜力的健康公司, JPM, FRE, CSCO。DRYS EPS -$8.49 (from Yahoo Finance), 似乎还不到能长期握着的业绩。 YMYD
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For simplicity, assume x % change in the price each day, holding n days, n/2 days going up, and n/2 days going down
The payoff for a two-day cycle is: (1+2x)(1-2x) =1 - 4x^2(x square), which for sure < 1 (since x sq > 0)
for n days, the final payoff is (1 - 4x^2)^(n/2), when n ==>无穷大, payoff ==> 0
Anyone does not believe it, try x= 3% and n = 200. |