如果今天的收盘价比昨天高，力量指数是正的，如果比昨天低，力量指数是负的。差值越大，力量越大。成交量越大，波动越强。
Force Index is greater when the market moves far on high volume and lesser when the market moves a short distance on thin volume。 When the market closes unchanged； Force Index equals zero。
当波动大，成交量高时，力量指数就大；当波动小，成交量小时，力量指数就小。如果市场的收盘价不变，力量指数就是零。
Smooth Is Better We can plot Force Index as a histogram； with positive readings above the zero line and negative readings below。 The raw Force Index looks very jagged； up one day； down the next。 It works better if we smooth it with an exponential moving average and plot it as a line。
平滑比较好 我们可以把力量指数画成柱状图，正数在0轴以上，负数在0轴以下。原始的力量指数看起来像锯齿，涨一天，跌一天。如果我们用指数平滑均线并把它画成线，那么就更好用了。
If we smooth Force Index with a long…term EMA of 13 days or longer； it will measure long…term shifts in the balance of power between bulls and bears。 To help pinpoint entries and exits； we should smooth Force Index with a very short moving average； such as a two…day EMA。
如果我们用13日或者更长的均线来平滑力量指数，它可以计算长期多头和空头的力量均衡。为了帮助找到进场点和出场点，我们应该用很短的均线来平滑力量指数，比如2日均线。
When the trend of our stock or future is up and the two…day EMA of Force Index declines below zero； it gives a buy signal。 When the trend is down and the two…day EMA of Force Index rallies above zero； it gives a sell signal。
当股票或期货的趋势是上涨的，2日均线力量指数下跌到0以下，它给出了买入信号。当趋势是下跌的，2日均线力量指数上涨到0以上，它给出了卖出信号。
The key to using a short…term Force Index is to bine it with a trend… following indicator。 For example； when the 22…day EMA of price is up and the two…day EMA of Force Index bees negative； it reveals a short…term splash of bearishness within an uptrend； a buying opportunity。 Once long； you have several exit strategies。 If you’re very short…term oriented； sell the day after Force Index turns positive； but if your time horizon is wider； hold until prices hit their channel line or the EMA turns flat。
使用力量指数的关键是配合趋势跟踪指标。比如，当22日均线的价格上涨，2日均线力量指数变成负数，它表明了在上涨时多头的崩溃，是买入时机。一旦做多，你要有几个出场策略。如果你是做短线，当力量指数变正数是卖掉，但是如果你的持有时间长，当价格碰到通道线再卖，或者是均线走平时卖。
Figure 5。11 Force Index … Two…Day EMA
图5。11 力量指数——2日均线
Spikes of a short…term； two…bar Force Index mark areas where trends exhaust themselves。 The downward spike in area A showed that the move from 56 to 43 was at its end。 Curiously enough； it was immediately followed by an upward spike in area B。 This pattern of two adjacent spikes； pointing in opposite directions； shows a great deal of confusion in the markets and is usually followed by a period of flat prices。 GE remained flat for almost two months following those two opposing spikes。
短期的指针，力量指数的2日线表明了趋势在哪里。区域A的下跌指针表明从56到43的下跌结束了。奇怪地，区域B的指针立刻出现了。这种模式，相邻的2个指针，指着相反的方向，表明市场很混乱，通常后面就是横盘。在2个指针之后，通用电子股票差不多横盘了2个月。
Technical patterns confirm one another when they give similar messages。 The downward spike in area C showed that the downtrend was being exhausted。 That bullish signal was followed by a bullish divergence between prices and Force Index； which traced a series of higher bottoms while prices tried to grind lower。 For fans of classical charting； there was a “reverse head…and…shoulders” pattern。 Finally； there was a kangaroo tail at the very low。 It looks as if GE keeps ringing a bell and telling us that the decline is over； it is ready to go up！ In area D； half…way through the rise from 37 to 53； Force Index starts tracing a bearish divergence； warning that bulls are losing power。 When the EMA follows this up by turning down in May； the bullish game is over。 It is the last good chance to take profits and position short。
当不同的技术模式发出相似的信息时，它们会互相确认。C区的指针表明下跌快到头了。这个多头信号后是价格和力量指数的看涨背离，当价格下跌时，跟踪到了一系列更高的底部。对于经典的画图迷来说，这是头肩顶反转模式。最后，在很低的地方出现了袋鼠尾巴。看起来通用电子好像在摇铃告诉我们下跌结束了，要开始上涨了！在区域D，从37涨到53的半路上，力量指数跟踪到了看跌背离，警告多头失去了力量。当5月份均线跟上来反转时，多头的游戏结束了。这是最后的兑现利润和做空的位置。
At the right edge of the chart the EMA is down and prices have just fallen to a new low； but Force Index is starting to trace a bullish divergence。 It tells you to tighten stops on short positions。
在图的右边，均线下跌，价格跌到新低，但是力量指数开始跟踪到看涨背离。它告诉要做好空头仓位的止损。
When the 22…day EMA of prices is down； and the two…day EMA of Force Index rallies above zero； it reveals a short…term splash of bullishness within a downtrend； a shorting opportunity。 If you’re very short…term oriented； grab a quick profit and cover the day after Force Index turns negative。 If your time horizon is wider； use the lower channel wall for the profit target。
当22日均线下跌时，2日均线力量指数上涨到0以上，它表明下跌时多头失败，是做空的时机。如果你是做短线，在力量指数变负数时快速兑现利润。如果你做长线，利用下面的通道边缘作为利润目标。
When the two…day EMA of Force Index spikes up or down； exceeding its normal peaks or lows by several times； it identifies an exhaustion move … a signal to take profits on existing positions。
当2日均线力量指数指针向上或向下，多次超过过去的顶或底，它确认了波动的耗竭——是兑现利润的信号。
When the trend is up and the two…day EMA of Force Index traces a sharp upward spike； eight or more times above its normal height for the past two months； it marks a buying panic。 The bulls are afraid of missing the train and bears feel trapped and cover shorts at any cost。 Such spikes tend to occur during end…stages of bull moves。 They tell you it is a good time to take profits on long positions。 Prices often rally to retest the spike day’s high。 By then the spirit is gone from the rally and other indicators start developing bearish divergences； warning of a trend reversal。
当趋势上涨，2日均线力量指数跟踪到上涨的指针，在过去2个月中，有8次或以上的次数在正常高度以上，这表明了买入的疯狂。多头害怕错过了火车，空头害怕被陷害，不管任何成本地回补空头仓位。这样的指针在多头的末期会出现。他们告诉你现在是兑现多头仓位利润的时候。价格经常会再次测试指针那天的高度。当上涨不再出现，其它指标开始出现看跌背离，这是警告趋势要反转了。
When the two…day EMA of Force Index traces a sharp downward spike during a downtrend； four or more times deeper than normal for the past two months； it marks an hysterical stage of the downmove。 It identifies a selling panic among the bulls； who are dumping their holdings at any price to get out。 Such spikes tend to occur at the end…stages of bear moves。 They tell you that it’s a good time to take profits on short positions。 Prices sometimes retest the spike day’s low； but by then most indicators are developing bullish divergences and an upside reversal is ing。
当2日均线力量指数跟踪到下跌趋势下跌的指针，过去2个月有4次或更多的次数比正常状态还低，它表明下跌的疯狂。它确认了多头卖出疯狂，他们不计成本地卖出自己的仓位。这样的指针发生在下跌波动的末期。它们告诉你此时最好兑现空头仓位的利润。价格有时会再次测试指针那天的低点，但是当大多数指标形成看涨背离时，反转快来了。
Spikes are somewhat similar to the kangaroo tails we discussed earlier （see “The Reality of the Chart” on page xx）。 The difference between them is that tails are purely price…based； while Force Index reflects volume as well as prices。 Tails and spikes identify panics among the weakest players。 Once they get flushed out； the trend is ready to reverse。
指针和我们以前说的袋鼠尾巴有点像（请看xx面“图的事实”）。它们之间的区别是，袋鼠尾巴单纯地建立在价格的基础上，力量指数反映了成交量和价格。尾巴和指针确认了市场中弱势一方。一旦他们出场了，趋势就要准备反转。
A Reversal Is ing Trend reversals do not have to e as a surprise； divergences between Force Index and price usually precede them。 If the market is trying to rally； but the peaks in Force Index are being lower； it is a sign of weakness among the bulls。 If a stock or a future is trying to decline； but the bottoms in Force Index are being more shallow； it is a sign of weakness among the bears。
反转来了 趋势的反转不一定就是突如其来的，力量指数和价格的背离通常会走在反转前面。如果市场想涨，但是力量指数的顶变得更低，那是多头变弱的迹象。如果一只股票或期货想跌，但是力量指数的底变的更浅，那是空头变弱的迹象。
Figure 5。12 Force Index … 13…Day EMA
图5。12 力量指数——13日均线
A longer…term Force Index； smoothed with a 13…day EMA； identifies longer… term shifts of power between bulls and bears。 When it is below zero； bears are in control； and when it is above that line； the bulls are in charge。 Divergences between the peaks of this indicator and price peaks precede market tops； whereas divergences between their lows precede important bottoms。
一个长期力量指数，用13日均线来平滑，能确认长期的多头和空头的力量。当它在0以下时，空头主导；当它在0以上时，多头主导。指标顶部和价格顶部的背离走在市场顶部之前，同理底部的背离走在重要的底之前。
In area A； Force Index traces a lower peak during the final price peak。 It reveals that bulls are weak and a top is likely。 A few days later； the EMA ticks down； confirming that a new downtrend has begun。 A mirror image of this pattern occurs in area B； where we see a lower closing price； a higher bottom of Force Index； and a few days later an uptick of the EMA； auguring an important rally。 Notice also the double bottom in that area … a kangaroo tail； followed by a retest of the lows。 This is one of many examples of patterns and indicators reinforcing each other。 In area C Force Index traces a bearish divergence and warns you that the bull move is over。 A few days later the EMA ticks down； and it’s all downhill from there。 The market keeps sending you messages … all you have to do is listen。
在区域A，力量指数跟踪到了次级高点，此时价格达到最后的顶峰。它表明多头变弱，可能到顶了。几天后，均线下跌，确认新趋势开始了。这个模式在区域B同样发生了，我们看见了更低的收盘价，力量指数底部抬高。还请注意那里的双底——一只袋鼠尾巴，后面是对底部的再次测试。很多模式和�