成交量可以衡量一個給定的金融產品在一段時間内的交易量。它是一個十分強大的工具，但這樣簡單的一個指標卻經常被忽視。成交量信息隨處可見，但是很少有交易者知道如何利用它來提高盈利、降低風險。
每一個買家都對應一個賣家來相應的售出股票，就像必須有一個買家來使賣家能夠擺脫他手中的股票。當長期的技術指標以及基本面發揮作用之後，這場發生在任意時間框架下的買賣家之間争奪最佳成交價位的戰争便導致了價格的波動。借助成交量來分析股票或者別的金融資產可以提高盈利、減少風險。
使用成交量的基本原則
當通過成交量來分析價格走勢的強弱時，我們有基本的指南：作為交易者，我們傾向於加入動能強大的價格走勢中，在價格弱勢的情況下我們不會跟進——在弱勢時，我們甚至會尋找反向交易的入場點。這些原則並不適用於所有情況，但是它們確實能夠很好地幫助交易決策。
成交量以及市場興趣
價格走勢的上升通常伴隨著上漲的成交量。更多的買方以及熱情才能夠維持價格的不斷上漲。價格升高而成交量減少表明市場缺乏興趣，這是一個市場將發生反轉的潛在信號。這很容易理解，但一個簡單的事實是，較小成交量對應的價格上升或下降不是一個很強的信號；較大成交量下的價格上升或者下降是股票市場發生巨大改變的強烈信號。
價格走勢以及成交量衰竭
在上升或下降的價格走勢中我們都可以看到走勢的衰竭：價格波動劇烈同時成交量大幅增加，表明當前趨勢即將終結。場外觀察者害怕進場後會失去更多，買方數量因此衰竭。在市場底部，價格的降低最終使一部分交易者平倉，導致價格波動性以及成交量同時增加。這種情況下如果出現價格缺口，我們會發現成交量下降。但是成交量在接下來幾天、幾週或者幾個月將如何影響價格，我們可以通過使用別的成交量指南分析。（相關閱讀《市場見頂的3個主要迹象》）。
熊市信號
成交量在識別熊市信號是非常有用的。比如，價格下降過程中成交量增加，然後價格升高、下降。如果價格沒有跌破前期低點，並且成交量在第二次價格下降後減少，那麼這通常就可以理解為牛市信號。
成交量以及價格反轉
在長時間的價格上升或下降之後，如果價格在小範圍内波動並且交易量巨大，那麼這通常表明反轉。
成交量、突破VS假突破
價格從波動區間或者是別的圖表形態最初突破時，成交量的增加表明價格力量的強勁。如果突破後成交量基本不變或下降表明市場缺乏興趣並很有可能是一個假突破。
成交量歷史
成交量應該與相對於歷史表現分析。將今日的成交量與50年前的成交量對比將會是毫無聯系的。成交量數據歷史越接近，他們相關的可能性就越大。
成交量指標
成交量指標在最常用的圖表平台中是以數學公式直觀體現出來的。每一個指標都有輕微的不同之處，因此，交易者也應該尋找最適合他們市場交易風格的指標。指標不是必需的，但是他們可以幫助交易決策過程。成交量指標有多種，下面將會呈現幾個使用示例：
平衡交易量指標（OBV）
平衡交易量指標是一個簡單卻有效的指標。從一個任意的數開始，如果價格走高，則加上成交量；價格走低，減去成交量，它以累計的方式顯示哪一只股票價格集聚。它也可以用來顯示背離，比如當價格上升但是成交量上漲緩慢、甚至開始下降。
蔡金資金流向指標（CMF）
價格的上漲通常會伴隨著成交量的上升，因此，該指標主要基於擴大的成交量並通過收盤價位於日内波幅的上部分還是下部分來決定價格走勢的強度值。當價格收於當日波幅的上半部分並且成交量擴大，則強度值為正數；價格收於當日波幅的下半部分，那麼強度值則為負數。CMF可以作為短期震蕩的交易指標使用。但是它更被常用來分析價格是否分離。
克林格成交量擺動指標（KVO）
KVO圍繞0軸上下擺動可以用來確認別的交易信號。KVO指標計算了一個給定週期内的成交量集聚（買方）和分離（賣方）。
成交量是一個十分有用的工具，你可以看到，它有很多使用方法。它有用來衡量市場強弱的基本準則，它可以用來確認價格走勢或發出反轉信號，可以幫助交易決策。簡而言之，成交量不是一個準確的開倉、平倉工具，但你可以借助它來查看價格走勢來推斷開倉、平倉位置。
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.
本文翻譯由兄弟財經提供
文章來源：http://www.fxstreet.com/education/technical/how-to-use-volume-to-improve-your-trading/2011/11/07/