怎樣使用移動平均線

 

趨勢

確定趨勢是移動平均線的一個關鍵功能，許多交易員用它來成為趨勢的朋友。移動平均線是滞後指標，這意味著它不能預測新的趨勢，但是能確定已經建立的趨勢。正如你從下圖中看到的，當價格高於移動平均線而移動平均處於上升時價格是上升的。相反的，交易員也可以利用下降移動平均線下面的價格確定下降趨勢。這一規則可以保證趨勢能在交易有利的方向進行。

 

勢頭

許多新手交易員問怎樣測量勢頭和移動平均數怎樣解決這一問題。簡單的答案是密切註視創建移動平均線的週期，每個時間週期對不同的勢頭提供寶貴的預兆。總體來說，短期勢頭可以通過20天或者更少的移動平均線判斷。觀察20到100天的移動平均線被認為是判斷中期勢頭的很好方式。最後，100天或者更長時間的移動平均線被用來策略長期勢頭。正常情況下15天移動平均線在測量短期勢頭時比200天的更合適。

 

確定一種資產勢頭的強度和防線是在圖表中設置三個移動平均線然後觀察他們之間的關系。這三個移動平均線通常代表短期、中期和長期價格運動的時間週期。在下圖中可以發現，當短期移動平均線在長期的之上而且兩個沒有接觸時，上升勢頭強勁。相反，短期移動平均線在長期之下，勢頭是下降的。

 

支撐

移動平均線的另一個常用功能是確定潛在的價格支撐。不需要太多經驗就能確定一個下降的價格會在一個重要的平均水平停止下降並逆轉。例如，在下圖中你可以發現200日移動平均線支撐價格從32下降後的反彈。許多交易員根據主要移動平均線預測反彈並使用其他技術指標進行確認。

 

 

阻力

一旦一種資產價格跌落到低於一個有影響的支撐水平，例如200日移動平均線，移動平均線成為一個阻止投資者將價格推到平均以上的強大阻力的情況並不少見。正如下圖中所示，這一阻力通常被投資者當作進行獲利交易或者關閉已有的多倉倉位的信號。如果你是一個持有多倉資產在主要移動平均線之下的投資者，這些水平是你關閉倉位的最好時機，因為他們可以對你的投資產生巨大的影響。

 

止損

移動平均線的支撐和阻力作用使他們成為管理風險的一個很好工具。移動平均線確定止損的能力使交易在損失擴大之前可以清空虧損倉位。如下圖所示，持有多倉倉位的交易在有影響的移動平均線之下設立止損可以減小很大損失。使用移動平均線設立止損訂單是任何成功投資策略的關鍵。

 

Moving Averages: How To Use Them

 

By Casey Murphy, Senior Analyst ChartAdvisor.com 

 

Some of the primary functions of a moving average are to identify trends and reversals, measure the strength of an asset's momentum and determine potential areas where an asset will find support or resistance. In this section we will point out how different time periods can monitor momentum and how moving averages can be beneficial in setting stop-losses. Furthermore, we will address some of the capabilities and limitations of moving averages that one should consider when using them as part of a trading routine. 

 

Trend 

Identifying trends is one of the key functions of moving averages, which are used by most traders who seek to "make the trend their friend". Moving averages are lagging indicators, which means that they do not predict new trends, but confirm trends once they have been established. As you can see in Figure 1, a stock is deemed to be in an uptrend when the price is above a moving average and the average is sloping upward. Conversely, a trader will use a price below a downward sloping average to confirm a downtrend. Many traders will only consider holding a long position in an asset when the price is trading above a moving average. This simple rule can help ensure that the trend works in the traders' favor. 

 

Momentum 

Many beginner traders ask how it is possible to measure momentum and how moving averages can be used to tackle such a feat. The simple answer is to pay close attention to the time periods used in creating the average, as each time period can provide valuable insight into different types of momentum. In general, short-term momentum can be gauged by looking at moving averages that focus on time periods of 20 days or less. Looking at moving averages that are created with a period of 20 to 100 days is generally regarded as a good measure of medium-term momentum. Finally, any moving average that uses 100 days or more in the calculation can be used as a measure of long-term momentum. Common sense should tell you that a 15-day moving average is a more appropriate measure of short-term momentum than a 200-day moving average. 

 

One of the best methods to determine the strength and direction of an asset's momentum is to place three moving averages onto a chart and then pay close attention to how they stack up in relation to one another. The three moving averages that are generally used have varying time frames in an attempt to represent short-term, medium-term and long-term price movements. In Figure 2, strong upward momentum is seen when shorter-term averages are located above longer-term averages and the two averages are diverging. Conversely, when the shorter-term averages are located below the longer-term averages, the momentum is in the downward direction. 

 

Support 

Another common use of moving averages is in determining potential price supports. It does not take much experience in dealing with moving averages to notice that the falling price of an asset will often stop and reverse direction at the same level as an important average. For example, in Figure 3 you can see that the 200-day moving average was able to prop up the price of the stock after it fell from its high near $32. Many traders will anticipate a bounce off of major moving averages and will use other technical indicators as confirmation of the expected move. 

 

Resistance 

Once the price of an asset falls below an influential level of support, such as the 200-day moving average, it is not uncommon to see the average act as a strong barrier that prevents investors from pushing the price back above that average. As you can see from the chart below, this resistance is often used by traders as a sign to take profits or to close out any existing long positions. Many short sellers will also use these averages as entry points because the price often bounces off the resistance and continues its move lower. If you are an investor who is holding a long position in an asset that is trading below major moving averages, it may be in your best interest to watch these levels closely because they can greatly affect the value of your investment. 

Stop-Losses 

The support and resistance characteristics of moving averages make them a great tool for managing risk. The ability of moving averages to identify strategic places to set stop-loss orders allows traders to cut off losing positions before they can grow any larger. As you can see in Figure 5, traders who hold a long position in a stock and set their stop-loss orders below influential averages can save themselves a lot of money. Using moving averages to set stop-loss orders is key to any successful trading strategy. 

 

 

本文翻譯由兄弟財經提供

文章來源：http://www.investopedia.com/university/movingaverage/movingaverages2.asp