趋势

确定趋势是移动平均线的一个关键功能，许多交易员用它来成为趋势的朋友。移动平均线是滞后指标，这意味着它不能预测新的趋势，但是能确定已经建立的趋势。正如你从下图中看到的，当价格高于移动平均线而移动平均处于上升时价格是上升的。相反的，交易员也可以利用下降移动平均线下面的价格确定下降趋势。这一规则可以保证趋势能在交易有利的方向进行。

 

势头

许多新手交易员问怎样测量势头和移动平均数怎样解决这一问题。简单的答案是密切注视创建移动平均线的周期，每个时间周期对不同的势头提供宝贵的预兆。总体来说，短期势头可以通过20天或者更少的移动平均线判断。观察20到100天的移动平均线被认为是判断中期势头的很好方式。最后，100天或者更长时间的移动平均线被用来策略长期势头。正常情况下15天移动平均线在测量短期势头时比200天的更合适。

 

确定一种资产势头的强度和防线是在图表中设置三个移动平均线然后观察他们之间的关系。这三个移动平均线通常代表短期、中期和长期价格运动的时间周期。在下图中可以发现，当短期移动平均线在长期的之上而且两个没有接触时，上升势头强劲。相反，短期移动平均线在长期之下，势头是下降的。

 

支撑

移动平均线的另一个常用功能是确定潜在的价格支撑。不需要太多经验就能确定一个下降的价格会在一个重要的平均水平停止下降并逆转。例如，在下图中你可以发现200日移动平均线支撑价格从32下降后的反弹。许多交易员根据主要移动平均线预测反弹并使用其他技术指标进行确认。

 

 

阻力

一旦一种资产价格跌落到低于一个有影响的支撑水平，例如200日移动平均线，移动平均线成为一个阻止投资者将价格推到平均以上的强大阻力的情况并不少见。正如下图中所示，这一阻力通常被投资者当作进行获利交易或者关闭已有的多仓仓位的信号。如果你是一个持有多仓资产在主要移动平均线之下的投资者，这些水平是你关闭仓位的最好时机，因为他们可以对你的投资产生巨大的影响。

 

止损

移动平均线的支撑和阻力作用使他们成为管理风险的一个很好工具。移动平均线确定止损的能力使交易在损失扩大之前可以清空亏损仓位。如下图所示，持有多仓仓位的交易在有影响的移动平均线之下设立止损可以减小很大损失。使用移动平均线设立止损订单是任何成功投资策略的关键。

 

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. 

 

 

本文翻译由兄弟财经提供

文章来源：http://www.investopedia.com/university/movingaverage/movingaverages2.asp