技術指標是基於交易工具當前以及之前的價格或成交量情況的數學統計方法。當被用作技術交易策略的一部分，指標可以幫助交易者識別特殊的、容易被肉眼忽略的交易機會。然而，如果你使用多種衡量價格走勢或成交量指標的話，你的分析將很容易受到迷惑。
這裡，我們將會回顧多種不同的技術指標，展示如何使用互補的技術指標來提高交易策略，並解釋選擇不同種類指標以避免多重共線性（使用多種類似指標造成的一種情況）的重要性。
交易指標的類型
根據每組指標的作用，通常將其分為下面四種類型：
趨勢指標衡量趨勢的方向以及強度，通常結合某種價格平均線形成的基線使用。動能指標通過對比隨著時間推移形成的價格變化來追蹤價格的變化速度。波動性指標可以提供一個給定市場的交易範圍、市場的加速或減速等信息。成交量指標表示已發生的交易活動的總量並分析價格波動的力量。
大多數情況下，指標本身不提供交易信號。交易者必須根據自己的交易邏輯，風格，風險承受能力，所選擇的交易工具來解讀交易指標的信息。將幾種不同種類的指標綜合到一個交易策略中（比如使用一個趨勢指標以及一個動能指標）將會比使用同類指標帶來更好的交易結果。
使用技術指標很重要的一點是試驗將它們應用於市場交易的各種創新方法。雖然技術指標通常有推薦的使用參數，但是交易者不能讓自己局限於這些規則。交易者可以依靠自己的研究以及對市場的觀察來建立屬於自己的交易指標。
綜合使用指標
為了提高市場分析（或者是成功交易系統的可能性），交易者需要使用互補的指標——那些相互協作，但是可以對市場走勢提供不同觀點以及可以幫助你做出交易決定的有意義數據。因此互補指標可以提供特別的——而不是冗餘的——信息，它們可以結合在一起使用來確認交易信號。
交易策略所使用的每一個指標都應該服務於不同的目地並可以就市場走勢提供獨特的視角——比如用來衡量動能或者評估總體趨勢。比如所謂的用於簡明扼要地介紹一個產品的電梯演講。交易者需要準確的說出指標存在於交易圖表中的目的。回答下面兩個問題十分重要：是什麼使得交易指標成為該交易策略的重要一部分？該指標可以提供什麼樣獨特的信息？
我們可以比較兩個交易系統來展示使用互補指標的優點。在第一個交易系統中，只有一個技術指標使用“止損反轉”策略來提供交易信號。第二個交易系統，增加了一個趨勢過濾器，如果條件不滿足，交易就不會執行。
上面“簡單的交易系統”顯示了只使用隨機擺動指標（一個動能指標）的“止損反向”交易策略，該指標週期為30，兩個平滑參數為3。當滿足下面兩種情況時做多：
• K慢線穿過D慢線
• K慢線在超賣區域20下方
滿足下面情況時做空：
• K慢線向下穿過D慢線
• K慢線在超買區域80上方
測試使用迷你標普爾500期貨的十年歷史數據（2002.6.17~2012.6.19），表現報告匯總在上述圖中。報告顯示，該指標的盈利系數為1.50，表明是可以盈利的。雖然盈利系數是可以接受的，但是如果添加一個互補交易指標的話，結果將會更好。
該指標在添加了一個可以幫助其判斷趨勢方向以及強度的指標之後表現更好。因此，一個簡單的交叉易移動平均線，時段分別為50和60.這就為交易設置了一個額外的入場條件：
對於做多，50日移動平均線必須在60日均線上方。做空，50日移動平均線需要在60日移動均線下方。
下圖顯示了同時使用隨機指標以及移動平均線指標的交易系統。在增加了交叉移動平均線指標作為過濾器之後，交易結果大大改善。隨機指標的盈利概率相對穩定在73.17%，結合了移動平均線指標之後盈利概率達到77.42%，平均淨盈利以及別的關鍵衡量指標都取得了顯著進展。通過使用一個互補指標，我們可以改善交易策略標準，並得到一個可以取得更多盈利的系統。
註意多重共線性
雖然使用多種指標的交易策略可以改善交易結果，但是錯誤的使用指標組合卻會產生危害。一些交易者可能會故意選擇相似的而不是互補的指標——為了相互印證一個交易信號。使用類似指標的問題是——比如兩種動能指標——它們實際上不會相互驗證，因為它們的只會產生重複的交易結果。這兩種指標貌似是在互相驗證，但是這僅僅是因為它們都是基於同一個數學計算公式。
多重共線性是一個統計系統，意思是對於同樣的信息進行多重統計。當類似的指標同時使用這種情況即發生。如果關聯程度非常高的指標用來量化市場活動性，比起那些沒有使用不同種類指標的交易策略，它的意義性要遜色很多。如果所有的指標都基於同樣的收盤價，比如，沒有產生新的信息，因此，不會產生真正意義上的相互確認。這就類似於在一個部門相似的市場條件下錯誤地試圖使自己的投資組合多樣化。
確認指標在市場中是否具有同樣的作用的一個簡單的方法就是在一張圖中回顧它們的交易結果。如果每個指標提供相似的信號並且以大概相同的方式移動，那麼它們就很有可能是共線性的，不應該在一起使用。
迷你標普500指數顯示了“重複努力”：隨機指標與順勢指標CCI同時使用。它們兩者都是動能指標，並且同時，例如，週期設置為30.我們可以從圖表中看到，這兩個指標幾乎相同的結果。交易策略中使用這樣的指標只會帶來害處，因為它們產生冗餘的交易信號，並且沒有真正的彼此驗證。第二個指標不應該產生同樣的交易信號，並且它應該減少第一個指標產生的信號並且確認更成功的信號——提高第一個信號的成功幾率或者數量。
交易者和投資者使用技術指標評估過去以及當前的市場行情並預測未來的價格走勢。使一個交易策略的成功率最大化，很重要的一點是，每一個技術指標都提供不同的觀點，並且對過去以及當前的價格活動協同合作提供全面的觀點，這樣交易者可以建造一個適合未來價格波動的交易模型。
A complementary approach to trading technical indicators
Technical indicators are mathematical calculations based on a trading instrument’s past and current price or volume activity. When used as part of a technical trading strategy, indicators can help traders identify unique opportunities in the markets that could be overlooked by simply viewing a price chart. However, you also can cloud your analysis by tracking too many indicators that measure the same qualities of price and volume.
Here, we will review the different types of technical indicators, demonstrate how to apply complementary technical indicators to enhance a trading strategy and explain the importance of selecting dissimilar indicators to avoid multicollinearity, a condition that results from employing multiple similar component techniques.
Indicator types
Indicators often are divided into four categories based on what each group measures:
Trend indicators measure the direction and strength of a trend and typically use some form of price averaging to establish a baseline. Momentum indicators track the speed at which prices change by comparing prices over time. Volatility indicators provide information about the trading range in a given market and its acceleration and deceleration. Volume indicators represent the amount of trading activity that has occurred and analyze the force behind a price movement.
For the most part, indicators by themselves do not provide trading signals. Instead, each trader must interpret the information to determine trade entries and exits based on his or her own trading logic, style, risk tolerance and even chosen trading instrument. Incorporating different types of indicators into a trading strategy (such as by applying one trend and one momentum indicator) will provide better results than using multiple indicators of the same type.
An important part of using technical indicators is to experiment with innovative ways of applying them to the markets. While technical indicators often have a recommended application, traders are by no means limited to those rules. Traders can rely on their own research and market observations to build a better mousetrap.
Combining indicators
To improve market analysis (and the odds of a successful trading system), traders should use complementary indicators — those that present different views of the market while working collectively to provide meaningful data on which to base trading decisions. Because complementary indicators provide unique — rather than redundant — information, they can be used together to provide confirmation for trading signals.
Each indicator that is used in a trading strategy should serve a distinct purpose and provide a unique perspective of the markets — such as to measure momentum or evaluate the overall trend. Like a so-called elevator speech used to explain a product’s purpose in a succinct, pointed delivery, traders should be able to explain concisely why an indicator is on a chart. Answering two questions is paramount: What is it that makes this indicator an important part of the strategy? What unique information does this indicator provide?
We can compare two trading systems to demonstrate the advantages of using complementary indicators. In the first system, only one technical indicator is used to generate trading signals for a simple stop-and-reverse strategy. For the second system, a complementary indicator is added that provides a filter, or confirmation, for the trades. If the conditions are not met, the trade will not be initiated.
“Simple system” (above) shows the basic stop-and-reverse strategy that uses only a stochastic oscillator (a momentum indicator) with the settings 30 for the length, 3 for the first smoothing input and 3 for the second smoothing input. The strategy enters a long trade when two conditions are met:
• SlowK line crosses over SlowD line
• SlowK line is below the oversold territory of 20
A short trade is entered when:
• SlowK line crosses under SlowD line
• SlowK line is above the overbought zone of 80
Ten years of historical E-mini S&P 500 futures data were included in the test (June 17, 2002 through June 19, 2012). The summary performance report is displayed on the chart. This tells us that the strategy shows a profit factor of 1.50, indicating that this strategy would be profitable. While the results are acceptable, adding a complementary indicator can improve performance.
The system is enhanced using a complementary trend indicator to help determine the direction and strength of the trend. For this, a simple moving average crossover is used with lengths of 50 and 60. This adds one additional condition to trade entries:
• For long trades, the 50-period average must be greater than the 60-period average.
• For short trades, the 50-period average must be less than the 60-period average.
“Trend filter” (below) shows the strategy that uses both the stochastic and moving average indicators. With the addition of the moving average crossover filter, the results are improved significantly. While the percent profitable remains relatively steady, 73.17% for stochastic only vs. 77.42% with the moving average filter, the average trade net profit and other key metrics show noteworthy improvement. By adding a complementary indicator, we are able to refine the strategy’s criteria to create a more profitable system.
Beware multicollinearity
While using multiple indicators in a trading strategy can improve results, using the wrong combination of indicators can hurt a system. Some traders may intentionally apply similar — rather than complementary — indicators with the objective of finding confirmation for a trading signal. The problem with using similar indicators — such as two momentum indicators — is that it really provides no confirmation at all because it produces only duplicate results. The two indicators may appear to confirm one another, but this is only because each is based on the same math.
Multicollinearity is a statistical term that refers to the multiple counting of the same information. It occurs when similar indicators are used at the same time. If highly correlated indicators are used to quantify market activity, the results are less meaningful than if different types of indicators are used as part of a strategy. If all indicators are based on the same closing prices, for example, no new information is produced, and therefore, no true confirmation is provided (see “Replicating efforts”). It is akin to trading similar markets in one sector in a mistaken attempt to diversify your portfolio.
A simple method of determining if indicators measure the same thing about the markets is to review their results on a single chart. If each indicator provides similar signals and they move in the same general manner, they likely are collinear and should not be used together. “Replicating efforts” shows a daily chart of the E-mini S&P 500 with a stochastic oscillator and the Commodity Channel Index (CCI) indicator applied. Both the stochastic and CCI are momentum indicators, and both, for this example, have been set to the same length of 30. We can see from the chart that the indicators produce nearly identical results. Using these two indicators together would be detrimental to a strategy because they produce redundant signals with no true confirmation. A second indicator should not catch the same signals, instead it should reduce the number of signals and confirm the more successful — either by percentage or magnitude — signals of the first indicator.
Traders and investors use technical indicators to evaluate past and current market conditions to predict future price movements. To maximize the odds of success for a trading strategy, it is important that each individual indicator provides a different view, and collectively a comprehensive view, of past and current activity so that traders can build a trading model better equipped to forecast the future ups and downs of market prices.
本文翻譯由兄弟財經提供
文章來源：http://www.fxstreet.com/education/technical/a-complementary-approach-to-trading/2012/10/11/