成交量可以衡量一个给定的金融产品在一段时间内的交易量。它是一个十分强大的工具，但这样简单的一个指标却经常被忽视。成交量信息随处可见，但是很少有交易者知道如何利用它来提高盈利、降低风险。
每一个买家都对应一个卖家来相应的售出股票，就像必须有一个买家来使卖家能够摆脱他手中的股票。当长期的技术指标以及基本面发挥作用之后，这场发生在任意时间框架下的买卖家之间争夺最佳成交价位的战争便导致了价格的波动。借助成交量来分析股票或者别的金融资产可以提高盈利、减少风险。
使用成交量的基本原则
当通过成交量来分析价格走势的强弱时，我们有基本的指南：作为交易者，我们倾向于加入动能强大的价格走势中，在价格弱势的情况下我们不会跟进——在弱势时，我们甚至会寻找反向交易的入场点。这些原则并不适用于所有情况，但是它们确实能够很好地帮助交易决策。
成交量以及市场兴趣
价格走势的上升通常伴随着上涨的成交量。更多的买方以及热情才能够维持价格的不断上涨。价格升高而成交量减少表明市场缺乏兴趣，这是一个市场将发生反转的潜在信号。这很容易理解，但一个简单的事实是，较小成交量对应的价格上升或下降不是一个很强的信号；较大成交量下的价格上升或者下降是股票市场发生巨大改变的强烈信号。
价格走势以及成交量衰竭
在上升或下降的价格走势中我们都可以看到走势的衰竭：价格波动剧烈同时成交量大幅增加，表明当前趋势即将终结。场外观察者害怕进场后会失去更多，买方数量因此衰竭。在市场底部，价格的降低最终使一部分交易者平仓，导致价格波动性以及成交量同时增加。这种情况下如果出现价格缺口，我们会发现成交量下降。但是成交量在接下来几天、几周或者几个月将如何影响价格，我们可以通过使用别的成交量指南分析。（相关阅读《市场见顶的3个主要迹象》）。
熊市信号
成交量在识别熊市信号是非常有用的。比如，价格下降过程中成交量增加，然后价格升高、下降。如果价格没有跌破前期低点，并且成交量在第二次价格下降后减少，那么这通常就可以理解为牛市信号。
成交量以及价格反转
在长时间的价格上升或下降之后，如果价格在小范围内波动并且交易量巨大，那么这通常表明反转。
成交量、突破VS假突破
价格从波动区间或者是别的图表形态最初突破时，成交量的增加表明价格力量的强劲。如果突破后成交量基本不变或下降表明市场缺乏兴趣并很有可能是一个假突破。
成交量历史
成交量应该与相对于历史表现分析。将今日的成交量与50年前的成交量对比将会是毫无联系的。成交量数据历史越接近，他们相关的可能性就越大。
成交量指标
成交量指标在最常用的图表平台中是以数学公式直观体现出来的。每一个指标都有轻微的不同之处，因此，交易者也应该寻找最适合他们市场交易风格的指标。指标不是必需的，但是他们可以帮助交易决策过程。成交量指标有多种，下面将会呈现几个使用示例：
平衡交易量指标（OBV）
平衡交易量指标是一个简单却有效的指标。从一个任意的数开始，如果价格走高，则加上成交量；价格走低，减去成交量，它以累计的方式显示哪一只股票价格集聚。它也可以用来显示背离，比如当价格上升但是成交量上涨缓慢、甚至开始下降。
蔡金资金流向指标（CMF）
价格的上涨通常会伴随着成交量的上升，因此，该指标主要基于扩大的成交量并通过收盘价位于日内波幅的上部分还是下部分来决定价格走势的强度值。当价格收于当日波幅的上半部分并且成交量扩大，则强度值为正数；价格收于当日波幅的下半部分，那么强度值则为负数。CMF可以作为短期震荡的交易指标使用。但是它更被常用来分析价格是否分离。
克林格成交量摆动指标（KVO）
KVO围绕0轴上下摆动可以用来确认别的交易信号。KVO指标计算了一个给定周期内的成交量集聚（买方）和分离（卖方）。
成交量是一个十分有用的工具，你可以看到，它有很多使用方法。它有用来衡量市场强弱的基本准则，它可以用来确认价格走势或发出反转信号，可以帮助交易决策。简而言之，成交量不是一个准确的开仓、平仓工具，但你可以借助它来查看价格走势来推断开仓、平仓位置。
How To Use Volume To Improve Your Trading
Volume is a measure of how much of a given financial asset has been traded in a given period of time. It is a very powerful tool, but it's often overlooked because it is such a simple indicator. Volume information can be found just about anywhere, but few traders or investors know how to use it to increase their profits and minimize risk.
For every buyer there needs to be someone who sold them the shares they bought, just as there must be a buyer in order for a seller to get rid of his or her shares. This battle between buyers and sellers for the best price on all different timeframes creates movement while longer term technical and fundamental factors play out. Using volume to analyze stocks (or any financial asset) can bolster profits and also reduce risk.
Basic Guidelines for Using Volum
When analyzing volume, there are guidelines we can use to determine the strength or weakness of a move. As traders, we are more inclined to join strong moves and take no part in moves that show weakness - or we may even watch for an entry in the opposite direction of a weak move. These guidelines do not hold true in all situations, but they are a good general aid in trading decisions.
Volume and Market Interest
A rising market should see rising volume. Buyers require increasing numbers and increasing enthusiasm in order to keep pushing prices higher. Increasing price and decreasing volume show lack of interest and this is a warning of a potential reversal. This can be hard to wrap your mind around, but the simple fact is that a price drop (or rise) on little volume is not a strong signal. A price drop (or rise) on large volume is a stronger signal that something in the stock has fundamentally changed.
Exhaustion Moves and Volume
In a rising or falling market we can see exhaustion moves. These are generally sharp moves in price combined with a sharp increase in volume, which signal the potential end of a trend. Participants who waited and are afraid of missing more of the move pile in at market tops, exhausting the number of buyers. At a market bottom, falling prices eventually force out large numbers of traders, resulting in volatility and increased volume. We will see a decrease in volume after the spike in these situations, but how volume continues to play out over the next days, weeks and months can be analyzed by using the other volume guidelines. (For related reading, take a look at 3 Key Signs Of A Market Top.)
Bullish Signs
Volume can be very useful in identifying bullish signs. For example, imagine volume increases on a price decline and then price moves higher, followed by a move back lower. If price on the move back lower stays higher than the previous low, and volume is diminished on second decline, then this is usually interpreted as a bullish sign.
Volume and Price Reversals
After a long price move higher or lower, if price begins to range with little price movement and heavy volume, often it indicates a reversal.
Volume and Breakouts Vs. False Breakouts
On the initial breakout from a range or other chart pattern, a rise in volume indicates strength in the move. Little change in volume or declining volume on a breakout indicates lack of interest and a higher probability for a false breakout.
Volume History
Volume should be looked at as relative to recent history. Comparing today to volume 50 years ago provides irrelevant data. The more recent the data sets, the more relevant they are likely to be.
Volume Indicators
Volume indicators are mathematical formulas that are visually represented in most commonly used charting platforms. Each indicator uses a slightly different formula and, therefore, a trader should find the indicator that works best for their particular market approach. Indicators are not required, but they can aid in the trading decision process. There are many volume indicators; the following will provide a sampling of how several can be used.
On Balance Volume (OBV)
OBV is a simple but effective indicator. Starting from an arbitrary number, volume is added when the market finishes higher, or volume is subtracted when the market finishes lower. This provides a running total and shows which stocks are being accumulated. It can also show divergences, such as when a price rises but volume is increasing at a slower rate or even beginning to fall. Figure 5 shows that OBV is increasing and confirming the price rise in Apple Inc's (AAPL) share price. (For more on the OBV, see On-Balance Volume: The Way To Smart Money.)
Chaikin Money Flow
Rising prices should be accompanied by rising volume, so this formula focuses on expanding volume when prices finish in their upper or lower portion of their daily range and then provides value for the corresponding strength. When closes are in the upper portion of the range and volume is expanding, the values will be high; when closes are in the lower portion of the range, values will be negative.
Chaikin money flow can be used as a short term indicator because it oscillates, but it is more commonly used for seeing divergence. Figure 6 shows how volume was not confirming the continual lower lows (price) in AAPL stock. Chaikin money flow showed a divergence that resulted in a move back higher in the stock. (For related information, see Discovering Keltner Channels and the Chaikin Oscillator.)
Klinger Volume Oscillator
Fluctuation above and below the zero line can be used to aid other trading signals. The Klinger volume oscillator sums the accumulation (buying) and distribution (selling) volumes for a given time period. In Figure 7 we see a quite negative number - this is in the midst of an overall uptrend - followed by a rise above the trigger or zero line. The volume indicator stayed positive throughout the price trend. A drop below the trigger level in January 2011 signalled the short term reversal. Price stabilized, however, and that is why indicators should generally not be used in isolation. Most indicators give more accurate readings when they are used in association with other signals.
The Bottom Line
Volume is an extremely useful tool and, as you can see, there are many ways to use it. There are basic guidelines that can be used to assess market strength or weakness, as well as to check if volume is confirming a price move or signalling a reversal. Indicators can be used to help in the decision process. In short, volume is a not a precise entry and exit tool, however, with the help of indicators, entry and exit signals can be created by looking at price action, volume and a volume indicator.
本文翻译由兄弟财经提供
文章来源：http://www.fxstreet.com/education/technical/how-to-use-volume-to-improve-your-trading/2011/11/07/