2011-04-15 13:39:25期指贏家

止損線可能就是你的生命線

止損線可能就是你的生命線

市場上常常聽到這樣懊悔的話語,“如果我早這樣就會少虧點錢”。“如果我不猶豫,我將狠賺一把。”然而接下來的市場便淹沒了說這些話的人,卻又回響起另一些人的感嘆。的確,我們的猶柔寡斷和貪心耽誤了數不清的機會和好局,不能自控的結果,就要付出慘重的代價。可能煮熟的鴨子飛走了,可能一次失誤斷送幾年或幾十年來的辛苦。我們看一下常用在期貨市場說明一般投資人在作出決定時拖延耽誤事情的典型例子。
  有一個人,他設了一個誘捕火雞的圈套,用一連串玉米粒引火雞走入一個門上裝樞紐的大籠子。他遠遠地用一根繩子聯在籠子的門上,當有足夠數目的火雞進入籠子時,他能把繩子一拉關往。但是一旦他關上,除非他親自走到籠子前就不能再打開,但這樣會把尚在外邊的火雞嚇走。

  一天,他已見到有12隻火雞在他的籠子裡。接著有一隻火雞溜出來,剩下11隻。他想:“剛才有12隻的時候我應該拉繩子關籠子的。也許再等一下,它還會走進去。”當他等這第12隻進籠子時,又有2隻火雞走出了籠了。他又想:“我應該滿足,有11隻也好,只要再有1隻火雞跑回籠子,我就拉繩子。”當他在等機會時,又有3隻火雞跑了出來,結果他落得個雙手空空。他的問題就在於他無法放棄原來已快到手的火雞數目,想像其中一些還會跑回去。這種態度正是典型的投資人無法認賠賣出的情況。他不斷期望期貨能恢復原價。教訓是:為了減低市場風險,停止數你的火雞。

  一筆交易必須設立一個止損點。“止損線可能就是你的生命線”。在市場面前,不可能永遠判斷正確,人人都會遭受失敗,為此我們要面對失敗。

  除了投資交易這一職業,世上也許沒有其他職業需要你承認錯誤。索羅斯深諳風險的重要,因此他成為馳騁世界的金融大鱷。李森固執自己的經驗和教條,一味追加投資,妄圖扭轉大勢,便搞垮了巴林銀行。我們沒有止損而丟失金錢一定能堆起一條哈大公路。必須要學會如何輸錢,這比學會如何贏錢更為重要。事實上,即使你只對一半,你也應該贏。關鍵在於每次搞錯的時候要反損失減到最少。

  我們不是神,我們是人。我們應記住一位金融巨頭的忠告“警悚者生存”。既然高利潤對面是高風險,我們就應在可怕的風險前面划上一條止損線,它可能就是我們的生命線。

國外頂級的資金管理

交易中人人都在說資金管理很重要,可是有多少人知道什麼是真正的資金管理。有交易系統,但資金管理做不好,最終還可能是虧損;高準確率的入市策略如果資金管理做不好,也會暴倉。良好的資金管理可以使交易系統風險最小化,盈利最大化。如果懂得資金管理,你便可以在對你不利的概率情況下,長期穩定的贏利。例如:有這樣一套交易系統,靠丟分幣來決定做多還是做空,人頭做多,字做空,就是這樣一套系統加上良好的資金管理最終還是贏利,可見資金管理在交易系統中起著決定性的作用。
  人們總在尋找成功交易的真正祕訣,但他們的心智卻促使他們在錯誤的地方做錯誤的事情,因此,他們尋求神奇的有75%準確率的系統來幫他們挑選對的股票 ,選對股票對成功交易來說,意義並不大。
  你可能會說 "你怎能那樣說?" OK,實際上,所有的成功交易者都知道成功交易的幾個因素。
  1、黃金法則,截斷損失並放足贏利;
  2、頭寸調整,也就是告訴你該買多少;
  3、嚴格執行上面兩點。
  當你領悟到交易的黃金法則 ,實際上就是告訴你,如何去限制損失,當你盈利時要盡量的持有,獲取最大的利潤。頭寸調整實際上是說,你在每一筆交易中該擔多大的風險。
  這是一個資金管理的學習軟體,它能幫助你了解什麼是成功交易中真正的因素,這個軟體不會教你如何去挑選股票,取而代之的是交易中更重要的方面“資金管理”以及放足盈利。這個學習過程有十關,難度日益增加。無論怎樣,你已知道了交易的法則,你也將學會成功交易的真正技巧。
  對這個游戲來講,你還須知道四個概念:
  1、了解H的重要性
  2、了解準確率與期望收益
  3、學會抓住盈利並放足盈利 
  4、學會資金管理技巧,讓自己擁有低風險的交易。
  這個游戲的設計是為了讓人們在游戲這樣一個更安全的環境中學會交易的法則 
  首先,你必須的明白H的原理,它代表風險,就是你介入交易是的初始風險。它表示在你分析錯誤時,為了保護資金所願意承擔的損失。
  例如:你在50元買進一支股票,然後下跌到你的止損位47元,你止損出局,此時你H的風險為3(50-47=3)。
  你想你的損失更小,利潤更大。當市場反向跳空開盤,你的損失可能已超出了你的止損點位,損失大於1H,或是到止損位後,你心智不願出局,造成損失大於1H,或是交易成本過高,使損失大於1H,那麼上述情況可能會大於1H。
  當你持有盈利的股票時,你希望它的盈利大於1H,例如:1H是3元,那15元的利潤就是5H利潤。假設你現在有一套準確率25%的交易系統,當你贏,你贏5H,當你輸,你輸1H,在這個交易系統中4次交易才對1次,但你最終還是盈利6元(15-3*3=6),想一想25%的準確率你都可以賺錢,這就是為什麼截住損失,並放足盈利如此重要的原因。
  該游戲第一關的準確率為60%,其中有55%是贏1H(及和你所擔的風險一樣),如果你承擔1000元風險,你的盈利也是1000元。有5%是贏10H(及擔1000元風險贏10000元)。虧損概率為40%,其中有35%的虧損是1H,有5%的虧損是5H  希望在這關中,你可以認識到5H虧損給你帶來的巨大痛苦。
  注意,這關中有60%的贏面,而且還有10H的盈利,但後幾關可沒這麼容易,接下來,我們談期望收益和概率。 
  期望收益和概率: 期望收益是一個數學公式,告訴你平均冒1元的風險,在大量交易後,你將獲得多大的收益 
  Casino的賭博游戲是負期望收益,長期玩,必輸無疑,除非你能改變它的幾率。但交易不同於  Casino,你可以設計成正期望收益的系統,最終在資金管理的幫助下,長期獲利。即久賭必贏
  大多數的人們有一個錯誤,他們尋找高準確率的系統,卻不是正期望收益的系統 
  一些最好的交易系統準確率卻在25%-40%。 
  例如:你在50元買入一支股票,然後在下跌1元後賣出,而盈利時卻長期持有,賺了15元,想一想輸只輸1元,賺時賺15元,哪怕你交易系統只有30%的準確率最終還是賺錢。 
  記住,你能賺錢是因為你學會了止損。
  期望收益統計比較難,但該軟體已幫你作了統計,你在VIEW採單下可找到,你也會知道每筆交易的勝率。交易是隨機,你可能會連輸10次,就像真實交易中的,你根本不知道下一筆是贏還是輸,但正期望收益會帶給你盈利。
  再次強調,期望收益不同於準確率,你要的是正期望收益而不是高準確率負期望收益的系統。
  在軟體第三關準確率會降低。系統的前六關,你比較容易獲得大H的利潤,在後四關你必須要通過捲動盈利來獲得H的利潤,就像真實的交易一樣,損失的頻率會加快,而大H利潤需要時間來積累。
  你如果持有一個盈利的部位,它可能只是1H的利潤,你就必須等待,等待大利潤的到來,或是只願意承擔多大的利潤回吐。當你獲利後,你必須考慮用利潤中多大的一部分拿去再投入 
  例如:
  建築公司的股票       風險 $1,000     結果贏了 $1,000   現在你有$2000
  現在你是用 $2,000繼續投入還是只投入部分?  讓我告訴你,全部再投入結果你有獲得1:1的利潤:
  你現在的情況是 
  建築公司的股票       風險 $2,000     結果贏了 $2,000  現在你有$4000
  現在你有3H的利潤,你是想再全部投入,還是只投入部分?如果你全部再投入你有可能獲得很大的H利潤,在真實的交易中你可能只繼續投入獲利的部分,然後將出場點上移,保住利潤。現在你決定在全部投入,很幸運,你又贏了
  建築公司的股票       風險 $4,000     結果贏了 $4,000  現在你有$8000
  你已有7H的利潤,如果你再全部投入,你將獲得非常大的利潤,另一方面,你也可能會有一個3H或4H的虧損,如果發生虧損,它也將會很大。OK,現在你決定將承擔的風險減小為$2,000.,你又贏了
  你現在的情況是
  建築公司的股票       風險 $2,000     結果贏了 $2,000  現在你有$10000
  你現在在承擔$1,000風險的情況下,已經有了9H的利潤,你現在知道讓利潤奔跑能夠產生大的利潤了,第七關就需要你用讓利潤奔跑的祕密去賺大錢。
  你現在已有了一個低風險的計划,你在玩第一關時時間可能較短,資本10000,你知道你有60%的勝率,你會盈利,你同樣知道會有一個大的利潤會來臨,你決定擔$2,000 或20%的資本,一路走來,最後你得到了一個5H的損失,現在你破產了,因為你擔的風險太大,盡管贏面和期望收益都站在你這邊,但你破產了
  在任何正期望收益的游戲中,都會有一個風險百分比會給你最佳的回報。當然擔的風險越大,你的收益就越大,同時,你的風險也越大,擔的風險越小,你的收益就越小,同時,你的風險也越小,如果你所承擔的風險太大,你將會破產。
  承擔一個在短期內不會使你破產的風險,那樣長期下來,你就能實現你的期望收益。
  每一關,你都必須學習應承擔多大的風險,每一關你都會領略到資金管理的藝術,你也可以發展更多適合自己的策略 
  如果你能在不破產的情況下,玩過10關,你就可以賺到你想賺的那麼多。
  現在打開"File",然後選"New Simulation…",視窗會跳出,然後選擇"Standard Game"點OK,游戲就會開始,你的目標是通過75次交易,最少使資本增值50%以上,然後才能進入下一關,如果你能只用5次交易就增值50%,可直接進入下一關
  它自帶5套交易系統:高準確率、低準確率、長線的、短線的,在無k線圖、技術指標和任何基本面的情況下,要完全通過頭寸調整來獲取盈利,讓你學習到資金管理中的真正的奧祕。它不難,但卻很少有人能做到。如果你在學完上述的資金管理後,你可以輕鬆的調整交易系統中的參數(例如系統準確率、長線還是短線等),你還可以將自己的交易系統輸入軟體中,尋找最適合自己的資金管理模式。

下跌市場補倉三大訣竅

補倉是被套牢後的一種被動應變策略,在具體應用補倉技巧的時候要注意以下要點:
  一、大盤未企穩不補倉。大盤處於下跌通道中或中繼反彈時都不能補倉,因為,股指進一步下跌時會拖累決大多數個股一起走下坡路,只有極少數逆市走強的個股可以例外。補倉的最佳時機是在指數位於相對低位或剛剛向上反轉時。這時上漲的潛力巨大,下跌的可能最小,補倉較為安全。
  二、弱勢股不補。特別是那些大盤漲它不漲,大盤跌它跟著跌的無莊股。因為,補倉的目的是希望用後來補倉的股的盈利彌補前面被套股的損失,既然這樣大可不必限制自己一定要補原來被套的品種。補倉要補就補強勢股,不能補弱勢股。
  三、把握好補倉的時機,力求一次成功。千萬不能分段補倉、逐級補倉。首先,普通投資者的資金有限,無法經受得起多次攤平操作。其次,補倉是對前一次錯誤買入行為的彌補,它本身就不應該再成為第二次錯誤的交易。所謂逐級補倉是在為不謹慎的買入行為做辯護,多次補倉,越買越套的結果必將使自己陷入無法自拔的境地。

Playing the Market's Money 玩市場的錢

也許讓你賺大錢的最佳辦法就是,準確區分你的初始資本和“市場的錢”(就是從市場上賺到的錢——hukan)。但你不能用此方法來管理客戶的資金,因為一旦他們看見你把之前賺到的利潤又吐回去的時候,他們會狂抓不已。

 假設你的目標是在未來一段時期內實現收益的最大化。只要不虧及你的初始資本,你願意為達到收益的快速增長而做任何事情。在此前提下,你可以設計一個特殊的系統,這個系統在初始資本上只冒很小的風險;但在“市場的錢”上冒最佳比例的風險。

 舉個例子,假設你在1月1號以$100,000作為初始資本。你的目標是到12月31日時,以初始資本的最小損失風險換取盡可能多的收益。那麼你應該這樣做:

    你應該以初始資本的1%來冒險,而在市場的錢上以最佳比例冒險(或近似地)。讓我們假設你的系統的最佳風險比例為10%。

 這個系統真正的優勢是什麼呢?一旦你有了利潤儲備,照此方法去做,你的利潤增長潛力會奇跡般地被放大。讓我假設你的第一筆頭寸是原油期貨。你的初始投入是$100,000 * 1% = $1,000。此時你的第二筆交易來臨,你已經在原油上有了$3,000的賬面利潤。現在,你可以投入的資金為,來自初始資本的$1,000,再加上賬面利潤的10%,即$300。因此,在同樣的系統下,你的第二筆交易可以投入的資金為$1,300。

 假設你對這種模式已經玩得很溜了。到三月份,你已經積累起$25,000的利潤。此時,你的潛在投入量為$1,000(初始資本仍然的1%),加上利潤$25,000的10%,也就是另外的$25,00。共計$35,00,占總資本($100,000 + $25,000)的2.8%,冒的風險比原來的1%翻了一倍多,但這並沒有危及你的老本(還是1%)。

“薄利多銷”和“暴利”原則的分野

系統成功的要素之一不在於高的勝率而在於是否有正的期望值。 “盡量追求盈利的幅度,以個別交易的巨大盈利來補償多次小額虧損交易的損失。”稱之為“暴利”原則;“盡量追求盈利的頻率,以盈利次數的壓倒多數來保證補償虧損交易的損失。”稱之為“薄利多銷”的原則。
關注高勝率還是關注期望值這正是所說的“薄利多銷”和“暴利”原則在戰略思路上的根本區別。 倡導“薄利多銷”並排斥“暴利”原則,其理由如下: 1.“世界上最頂尖的跨國企業”採用的是“薄利多銷”的原則; “…系統的穩定性越高,系統在實際使用中的可靠性越高。系統的穩定性可由系統仿真的統計分布參數來確定。系統仿真結果的標準離差越小,則系統的穩定性越高。…從單純統計學的觀點來看,後—派投資理念所指導的交易方法(指“薄利多銷”)一般具有更高的統汁穩定性。 ”
了解一點跨國企業的發展史就會發現他們大多經歷過“暴利”時代,在此階段產品利潤豐厚,銷量大增從而使企業獲得了巨大的發展。而後來大多採用“薄利多銷”的營銷策略,是因為市場環境的改變,競爭的加劇和政府法規政策約束的結果,如反壟斷法的出台等等。毫無疑問,這是一種順應市場發展的必然選擇。如若市場環境許可,跨國資本決不會排斥“暴利”的策略,更不會放棄“暴利”的機會。就拿汽車來說,看一看近幾年美國通用在上海“別克”車型上所獲得的暴利,一輛車何止是幾百美元!因此,只看見跨國公司採用的是“薄利多銷”的原則,而不去挖掘這一營銷策略背後所隱含的適應競爭環境和消費心理的市場哲學,是遠遠不夠的。正因為如此,交易思路與其是“形似”而非“實是”。――“盡量追求盈利的頻率,即以盈利次數的壓倒多數來保證補償虧損交易的損失。”從頻率而不是從期望值來考慮,這就是交易思路上的根本侷限。個人的實踐證明,“多一隻眼睛看世界”――站在期望值的高度去建立我們的系統交易策略,即從盈利的頻率和盈利的效率兩方面來考慮會更好一些。成功的道路會更寬一些。
對所謂“暴利”原則的描述,“盡量追求盈利的幅度,以個別交易的巨大盈利來補償多次小額虧損交易的損失。”我本人並不完全同意書中的定義。我個人認為比較經典的表述應該是“截短虧損,讓利潤捲動起來”(“…CUT YOUR LOSSES SHORT AND LET YOUR PROFITS RUN”――<TRADE YOUR WAY TO FINANCIAL FREEDOM>---Pxvii,P39,41,83,234,314)。“止損獲利”是不夠確切的。這是華爾街的一句古老的格言,V K. THARP在書中多次引用,並進行了詳細的闡述。有興趣的朋友可以一讀,深刻理解這一點相信對你會有幫助。
下面是一位網上朋友對實戰範例的研究和評述: “…我把SP500指數期貨2號短線交易系統·的實際操作記錄標在S&P500該期的圖上。 可以看到,基本上都是些當日沖銷的操作,而且於盤整期操作最為頻繁。當遇到96年一月底二月初的一段強勁的單邊上昇行情時,系統在此時無法發出買入信號,並且連續兩次做空,錯過了很多機會。也就是說,他的系統基本上是反趨勢為主的,也是存在無法追蹤趨勢和適應波動幅度突然發生巨大變化的問題的,正如他所說,是薄利多銷,而非捕捉難得的市場機會。但他最大的一次操作虧損來自做多次日的反向跳空低開,具有相當大的破壞力,其實並非市場意外事件,該次下挫的幅度遠遠小於前期單邊行情的上昇幅度,而且類似的大陰線在整個測試期間出現過3次。因此如果系統在單邊上昇的時候不能捕捉到類似幅度的盈利,那麼系統對這樣潛在危險的抵抗能力就值得懷疑。”
非常抱歉,當時覺得有價值就隨手摘錄了,未能留下網友的網名等完整的資料。以上評述僅供有心的朋友參考,如手頭有S&P500的歷史資料,也可對照觀摩。我也作了對照,我覺得網友的評述基本符合事實。 個人以為,站在期望值的高度,“聽天命,盡人事”――如有利潤不必急於落袋為安,而應任憑市場波動,放手一博。這一單最後能有多大的利潤由市場決定,這是“聽天命”;如有虧損則一定把他限制在一定的範圍內,這風險必須是由自己控制,決不能聽憑市場擺布。這是“盡人事”。以上就是我對交易系統設計思路的理解。(盡管在實戰中要做到這一點要求交易者必須具備較高的心理素質這一點以後再談。)
按照對市場波動特徵(隨機性,偏向性,周期性等等)的理解,“薄利多銷”的方案具有更高的統汁穩定性的論點也並沒有可靠的依據。傳統的金融理論在有效市場假設的基礎上,假定市場的收益率變化服從正態分布。這一假定已經被越來越多的研究證明並不切合實際。“事實上,市場收益率分布明顯偏離正態分布而呈現一種“‘胖尾’特徵。”(<金融市場的非線性:混沌與分形>)根據現代非線性科學的混沌理論和分形理論,近十幾年來國內外的學者對國際匯率期貨市場,黃金白銀市場,歐洲股票市場和上證綜指,股票指數等等的一系列研究表明(資料索引同上,略),市場價格所構成的時間序列均呈現非線性且有低維混沌特徵。根據對金融市場的非線性特徵研究最新進展的評述結論:“金融市場經常會出現異常波動,傳統的正態分布的標準差標度性質已經不能應用於分析市場風險,必須用分形維數,H/S分析,李雅普諾夫指數,Komogorov熵度量分形市場。”
因此“從單純統計學的觀點”得出的結論並不能讓人信服。關注金融市場的非線性科學研究的最新成果,也許是我們在實戰中進一步理解和把握市場價格波動特征的一條好線索。

注碼法的價值

我被問的最多問題之一,是關於注碼法的價值。[注碼法]是指通過押注大小的變化,來減低或削除賭場所占優勢的方法,即很多朋友說的[賭欖]。

  有很多騙錢作家,經常推出一些注碼法,聲稱可以利用這些方法,輕易在賭場的純運氣的游戲中取勝,例如百家樂,大細,輪盤,番攤,這些方法都是教你在連續輸之後加注,直至贏回一把。

  這些系統的邏輯,是假定你始終總會嬴一次,到時就可把之前輸掉的,即使不全贏回來,也大部份贏回來。這種愈輸愈加注的方法,的確經常給玩家許多次贏到小利,因而沾沾自喜。然而,只要一次倒霉,那玩家便會把以前嬴的小錢全部輸回去。

  它們是建基於一個錯誤的概念,就是,久未出現的賽果,即將出現的可能性便愈大,押注便愈有利。這簡直是謬論,輪盤或大細每次開出的結果,都是獨立性的,不能記憶之前的事吧。過去已發生的,和未來要發生的,都是毫無關連的。換句話說,沒有一個賽果是"該發生了"。

  我並不完全反對使用注碼法。如你樂於使用就用吧。如果你的目的,是寧願嬴取多次小錢,偶而輸一次大錢,那麼用愈輸愈加注的系統是可以的。

  如果你不介意許多次小損失,而想要一次嬴大利的話,那愈贏愈加注將幫上你。

  雖然如此,最終的輸錢預期凈值,都會與理論上的賭場占先度接近。說到底,所有的注碼系統都是沒用。

  如你不信,請參考大英百科全書 Brittanica,關於賭博的一個專題: "有一個叫機會的成熟性之學說,或叫蒙地卡羅謬論,是賭客常犯的,就是錯誤地假設,每次開出的結果不是獨立的,並且出現偏低的結果,會於短期內平反過來,得以達致平衡。市面上大部份的系統,主要都是根據這個謬論而發明的;賭場當然很鼓勵玩家用這樣的系統,同時很歡迎這類忽視機率法規,和不相信賽果獨立性的賭客。"

  大英百科全書還提及有關輪盤的:"最久和最常用的注碼法,是叫輸後加倍法 (Martingale),教你每輸一次,注碼便加大一倍。這大概源自於輪盤的發明,此後,每天都有刪刪減減類似的新發明,真是層出不窮。多年過後,這些"必嬴系統"最終都不管用,依然要敗給賭場那個不敗的系統,那個克服不了的 0 或 00 的占先度。"

  只要我還在,我知道永遠有人,在數學上向我挑戰,繼續設法和我辯論。他們將聲稱,以其開明,不會被既定之機率理論所規限,而另覓數學真相。他們還將聲稱,電腦分析不能穿破注碼系統,因為計算器不賭錢,是人賭。他們會吹盡一切,去誘使你買那些系統。

  事實是,千百年來,還沒人能證明一個行之有效的賭博系統。賭場還是日益興旺。沒人打敗過這些游戲所依靠的數學理論,以後也永遠不會。

從倉位大小看收益期望值的穩定性

先我們來做一個簡單的傳統拋硬幣賭博實驗,借以說明倉位大小影響收益期望值的穩定性。

假設硬幣的正面的概率為55%,反面為45%,那麼
1、如果每次下注1元,每次收益期望值=55%*1-45%*1=0.1元。這樣下注10次才能平均賺得1元。
2、 如果每次下注0.1元,每次收益期望值=0.01元,這樣要下注100次才能平均獲得1元。
3、 如果每次下注0.01元,每次收益期望值=0.001元,這樣要下注1000次才能平均收益1元。

雖然這三種情況都能賺1元,但這3種情況的風險度完全不一樣。有人已經做了一個概率統計,結果如下:

贏利區間(元) 拋10次 拋100次 拋1000次
-10到-8 0.45% 0.00% 0.00%
-8到-6 2.29% 0.00% 0.00%
-6到-4 7.46% 0.00% 0.00%
-4到-2 15.96% 0.18% 0.00%
-2到0 23.40% 18.09% 0.08%
0到2 23.84% 68.30% 99.85%
2到4 16.65% 13.35% 0.06%
4到6 7.63% 0.07% 0.00%
6到8 2.07% 0.00% 0.00%
8到10 0.25% 0.00% 0.00%

我把以上的概率分布資料生成了一張圖表,可以一目了然地看出小倉位下注的安全性。同理,小倉位順著行情的方向玩股票或者期貨長期下來總會有收益,風險相對小得多。

請你拿出計算器機算一下,這3種情況的總贏率和總賠率的大小。
10次 100次 1000次
總贏率 50.5% 82% 99.92%
總賠率 49.5% 18% 0.08%

總贏率=所有贏利概率之和
總賠率=所有失敗概率之和

我們可以看到,當成功率為55%時,在10次贏1元的情況下,成功的總概率為50.5%,風險是相當大的。在100次贏1元時,成功的總概率為82%,這種情況還可以投機。在1000次贏1元時,成功概率高達99.92%,可以完全保證長期贏利。

如果把1 元換成1萬元,在同樣的成功率為55%的贏利水平的市場裡,大倉位可以在較短的時間內賺到1萬元,而小倉位要在更長的時間裡才能賺到1萬元。沒有耐心的人,平時沒有大機會的條件下習慣滿倉殺進滿倉殺出,風險還會大幅增高。如果在機會來了時,分倉慢慢買入,心平氣和,做對了行情時逐步正金字塔加倉,做錯了行情時及時斬倉或者減倉出來,既減小了風險,又能保證穩定適當的利潤,這是比較好的最普通的交易策略。

本實驗的好處在於,它把其它一些復雜的因素隔離開來,只考慮了倉位因素對收益穩定性的影響。事實上,做對了盡量持有和正金字塔漸步加倉,做錯了盡快斬倉或者減倉,贏利概率還會大幅提高。除此之外,對資金管理的其它策略也能大幅增加收益,減少風險。

以時間為代價換取收益的穩定性的辦法應該作為職業炒手的一種意識。根據行情客觀情況來決定輕倉駕御還是重拳出擊,這要根據自己的水準和經驗來決定,每次都採取輕倉的策略並不算合理,有沒有這種輕倉意識才是最重要的。當有大行情大機會來時,為什麼不重拳出擊呢?問題在於不能習慣性地天天重拳出擊!

國外大基金投資非常穩健,年收益一般在20%~30%已經很了不起了,它們更強調穩定的收益策略,不在一時的大贏。短時的大贏策略容易帶來短時的大輸,必然造成資金帳戶的極大風險,對於任何基金都是十分危險的舉動。分散小規模投資也許是最好的辦法,剛好體現了本實驗的實質所在。在同一個市場或者相關性很大的市場裡分散投資效果不好,對於有較強相關性的品種之間搞分散投資將失去分散投資意義,這恰好是投資界不太明確的地方。

最後提醒,投機是一項複雜的活動過程,不是僅依靠倉位就能解決投機中所有的問題,倉位僅是一項不能忽視的重要問題。

The Foundations of Money Management

People have always wanted to win at the stock exchange. But the existing industry of attracting money to the market with promising-named books, metastocks and finams of all kinds exploits our common prejudices, making us seek wrong things at wrong places. We're busy looking for a "magic" indicator or trading system that will keep us winning 90% of the time.

I've found such a system. With numerous tests it almost never had under 90% profitable trades. The results of one such a test are given in Table 1 in Omega Research TradeStation format. The code for the system is in Appendix 1; you may copy it to Omega TradeStation or SuperCharts and go along winning (in the sense they usually mean winning, that is, having a profit on most trades). The system's main secret is a pseudo-random number generator (too "pseudo" in TradeStation, but doesn't matter much). Then it all goes as usual: if the position is profitable, close it. If the market goes against us, turn investors. Having enjoyed working and socializing with customers of two brokerages over a couple of years, I can insist that is just what most traders do - except the fact they formally replace the random number generator with analytic forecasts, indicator signals, the neighbor's opinion in the pit or just a momentary impulse. The problem is that winning at an exchange and earning money at an exchange are far from being the same.

Surely, the profit seen in the Table 1 example is casual, a result of a lucky dice roll, whereas it would not be profitable in most cases. But if one changes the system entry parameters to more reasonable levels, i.e. sets mmstp=1, pftlim =4, maxhold =10, this will make the system profitable in most tests.

So exploiting the principal idea of speculation - close losing trades fast and let profits grow - combined with money management allows to earn money even from random trades. Most people act just opposite to this principle; they let losses grow, hoping the market turns and proves how right have they been, and quickly close their profitable positions to prove how right they're at the moment. Most beginners and many self-styled pros, as our experience shows, are sure that the skill of market forecasting equals the ability to earn money at the market. Getting a profit on a given trade for them means proving their prognostic abilities and, consequently, their skill in making money.

A person unfamiliar with trading as a business could be puzzled by the fact that "successful investing and trading have nothing in common with forecasting"*. There is bad news and good news. The bad news is: markets cannot be prognosed. The good news is: one doesn't need to do that to have profit. We are concerned not with getting a profit on every trade, but on making large sums when we're right. The number of profitable trades may in this case be less than losing, that is, it is possible to use worse-than-random forecasting!

As a famous trader Paul Tudor Jones said: "I may be stopped four or five times per trade until it really start moving". That is, Paul may win only on a measly 20-25% times! Yet he'd had three-figure (percents) of income in five consecutive years with very low capital corrections1. Almost 100% of Steve Cohen's very large profits are taken off 5% of trades, and only 55% of his trades are profitable at all. Despite that in the last seven years he'd made 90% per year on the average, and had only three losing months (the worst losses were -2%)2.

The widely used by professional methods of trend following, as a rule, bring about 30-40% of profit. Profits or losses in any given trade do not matter - as long as the amount of money earned per average trade is positive. This value is called mathematical expectancy. The mathematical expectancy equals the sum of products of profit probabilities minus the sum of products of losses probabilities, multiplied by the losses' size

                                                                

Simplified, the expectancy may be estimated as the probability of profits multiplied by the average profit minus probability of losses multiplied by the average loss. In terms of the Omega Research TradeStation this looks like:

                                                          

Table1.

Total Net Profit$562.70Open position P/L($75.60)
Gross Profit$1,269.40Gross Loss($706.70)
Total #of trades276Percent profitable92.75 %
Number winning trades256Number losing trades20
Largest winning trade$54.90Largest losing trade($126.50)
Average winning trade$4.96Average losing trade ($35.33)
Ratio avg win/avg loss.14Avg trade (win &loss)$2.04
Max consec.Winners39Max consec.losers2
Avg #bars in winners1Avg #bars in losers17
Account size required$177.30Return on account317.37%

In a newsgroup discussion one follower of Elliott's theory said: "Market is no gambling - we make no bets". Not being an Elliott adherent, for whom everything is pre-arranged, we do make bets. Since the result of any trade is unknown, any trade is a bet where we win or lose a certain sum. The principal difference between gambling (betting) and market trades (speculations) is first, that gambling creates its own risks and speculations re-distribute the risks already present on the market; second, the on a market a trader is able to provide himself with a statistical advantage, that is, a positive expectancy.

Let us review betting on a color when playing roulette. There are 18 red sectors, 18 black and the zero. The expectancy of winning for a single bet on a color is 18/37 - (18+1/37) = - 1/37. On the average the house wins from a single gambler this amount multiplied by the bet size. Despite the fact some gamblers may win a lot, it is the house that wins always - because of the biased expectancy, not because the dealer knows where the ball stops.

Appendix 1. A system giving over 90% profitable trades.
{*********************************************************
Random System №1.
Copyright (c)2001 DT
Parameter values by default: mmstp =1,pflim =4,maxhold =10
**********************************************************}
Inputs: Bias(.025), {Random entry parameter}
mmstp(100), {Stop loss parameter}
pflim(.1), {Profit target limit}
maxhold(50); {maximum holding period};
Var:Trigger(0),Signal(0),ATR(0),num(1);
trigger =random(1);
if trigger < bias then signal = -1;
if trigger >1 - bias then signal =1;
ATR =XAverage(TrueRange,50);
{ Random Entry}
If signal =1 then Buy("Random_Mkt.LE")num contracts next bar at open;
If signal =1 then Sell("Random_Mkt.SE")num contracts next bar at open;
{ Standartized Exits}
if marketposition >0 then begin
ExitLong ("MM.LX")Next Bar at EntryPrice -mmstp*ATR stop;
ExitLong ("Pt.LX")Next Bar at EntryPrice +pflim*ATR limit;
if barssinceentry >=maxhold then
ExitLong ("Hold.LX")at close;
end;
if marketposition <0 then begin
ExitShort ("MM.SX")Next Bar at EntryPrice +mmstp*ATR stop;
ExitShort ("Pt.SX")Next Bar at EntryPrice -pflim*ATR limit;
if barssinceentry >=maxhold then
ExitShort ("Hold.SX")at close;
end;

Appendix 2. The simplest system number 2. {*************************************************************
The Simplest System №2.
Copyright (c)2001 DT
**************************************************************}
Input:Price((H+L)*.5),PtUp(4.),PtDn(4.);
Vars:TrendLine(C),LL(99999),HH(0),num(1);
if MarketPosition <=0 then begin
if Price < LL then LL =Price;
if Price cross above LL +PtUp *.001 then begin
buy("Simpl.LE ")num contracts next bar at market;
HH =Price;
end;
end;
if MarketPosition >=0 then begin
if Price >HH then HH =Price;
if Price cross below HH -PtDn *.001 then begin
Sell("Simpl.SE ")num contracts next bar at market;
LL =Price;
end;
end;

Appendix 3. Data output to a file to compute mathematical expectancy {*************************************************************
Expectancy Output
Copyright (c)2001 DT
**************************************************************}
Var:RMult(1),R1(1),Trades(0);
Trades =TotalTrades;
R1 =PctUp *.001 *BigPointValue;
RMult =PositionProfit(1)/R1;
If barnumber =1 then
print(file("D:\TS_Export \M trading.csv"),"Qty",",","Profit",",","Initial Risk",",","R multiple");
If Trades <>Trades [1 ]then
print(file("D:\TS_Export \M trading.csv"),Num:10:0,",",PositionProfit(1):10:4,",",R1:10:4,",",RMult:10:4);

To be just we should mention that it is possible to create a "gambler's advantage" - so a mathematician Edward Thorp has developed strategies with a positive expectancy for playing blackjack, which he'd successfully used in Las Vegas gambling houses. When they stopped letting him in, he published his methods1, after which blackjack rules had to be altered to remove the gambler advantage. In late sixties Thorp took interest in shares market and became a manager for a private investing partnership: " Our significant rival then was a Harry Markowitz, a future Nobel prize winner. After 20 months we had +39,9% profit compared to Dow Jones' +4,2%. Markowitz went negative in a couple of years, and we're satisfied with our stable results… about 20% yearly (standard deviation around 6%0 and zero correlation with the market".

The market allows to play games with a positive expectancy. This is a necessary condition for successful stock trading. Actually, as Ralph Vince says, "it doesn't matter how negative or how positive; only positive or negative matters". A doubtful claim from our point of view; a larger positive expectancy is superior to a smaller one.

Besides expectancy, most traders have problems understanding risk. For instance, a historian by education, (former) head of a regional investing company with assets over a million dollars by summer 1997 was sure that "risk doesn't exist so it cannot be measured" and also sure that "one shouldn't sell shares at a loss". What can one say about amateurs then… Risk does exist and it can be measured. It is considered that risk is a volatility measured as the standard deviation of the changes of actives traded. This holds true for investing risk, speculative risk is more adequately defined as standard deviation of capital changes. By both those definitions risk is heavily underestimated. According to Murphy's laws, the worst is yet to come; We shall employ the following definition: risk is the amount of money we are ready to lose before withdrawing from a losing trade.

Before opening a position it is necessary to define the point where we close the position wit a loss to save capital - the so-called stop loss1, or where we open an opposite position, having made sure of our mistake concerning the market direction - the so-called stop-and-reverse. The difference between the entry point and the stop loss point multiplied by the number of lots is the starting risk or 1 R2, independent of how and in which units we measure the stop level, be it dollars, percents, volatility units or six-packs. This definition of risk is not equal to the first definition - the risk may be many times the 1 R if the stops are not executed due to lack of discipline3, gaps against the position or unexpectedly high slippage. The profit, then, can be defined in units of risk per share or in multiples of R. In terms of multiples the basis rule of speculation will be formulated as: keep losses at the level of 1 R as long as possible and let profits reach many times R.

The expectancy in multiples of R will mean how much can we win or lose per unit of risk in an average trade. To calculate expectancy in terms of multiples of R we must place the results of our trades in a table with the following columns:


Number of lotsProfit or LossStarting riskMultiple of R

The Profit or Loss must take into account broker commissions and slippage. Multiple of R is calculated by dividing the second column by the third. Then to calculate expectance it is enough to add up the values of the fourth column and divide by the number of trades. This method is also works with "intuitive" trading.

 

So, we do have a winning strategy - what next?

We can open a brokerage account and bet all our capital with the maximal leverage.

Here the most important thing - the money management begins. To clear the situation here is a pair of facts. Ralph Vince invented a game, where bet size was the only moveable parameter. He chose forty doctors of sciences (i.e. not the dumbest people at least) as players, none of which were professional traders or studied statistics. The doctors played a game where 100 random trades were generated, one by one. Every one began at $1000, and before every trade one had to make a single decision - how much (up to 50% of the capital) to bet. 60% of the time the players won their bet, and 40% of the time they lost their bet. This game has an expectancy of 20 cents per dollar risked, i.e. in the long run the player can receive 1 dollar 20 cents per dollar. The academicals made their 100 bets, enough to resolve the expectancy. Making the same trades, they finished the game with different results. Guess how much of them increased their starting capital? Two of forty. 95% of doctors lost money playing a game with a positive expectation!1

Van Tharp made an even more striking example. In an Asian Tour for Dow Jones Telerate TAG (Technical Analysis Group) he gave lectures in 8 cities before 50-100 listeners each time, most of them professional traders for large companies or banks that traded shares, bonds or exchange rates on Forex. In an analogous game over a half of highly professional traders lost!2 Another personal example - a trader offered a similar game to a friend employed by Charles Schwab as a leading analyst. At the first level the distribution of multiples of R with an expectancy of 0,45 and 60% profitable trades. To get to the second level one had to make 50% profit in 100 trades. The result was "I cannot get to level 2 in a day!"3. In 1991 Brinson, Singer and Beebower published a research of the efficiency of 82 portfolio managers in a 10-year period, which showed that 91,5% of all profit was generated by asset distribution3. The asset distribution meant the division of capital between cash, shares and bonds. Only 8,5% of profit was due to buying and selling the right stocks and bonds at the right time.

Let us play the game described by Vince. If there was no risk, i.e. we knew the result of each trade beforehand, it would make sense to bet all the capital each time. So every player would have gained $1000 ..(1.2 ^100)=$82,817,974,522.01 .

In reality, if we bet all $1000 on the first trade, we have a 40% risk to lose all at the first attempt. Even if we win and have $2000, betting all on the next trade would be exactly as insane.

Now suppose we bet $200 at a time. So if five first trades are losing, we again lose all. The probability of such an event is small, just over 1%. But are we ready for such a "small" risk, if we can lose all the money? Suppose we lose in the first two trades (16% probability), so we'd lose 40% of the capital. Beginning from the next trade we must gather 67% of profit just ot restore the starting capital. This effect is called "asymmetric leverage"5.

Table 2 shows that loses of over 50% need improbably large profits just to recover; so if we risk relatively large sums and lose our chances to end up wit a profit are negligible.

The result in the doctors' case is explained not only by oversized bets. A widely spread pitfall is so-called "gambler's error": People tend to suppose that after a series of losses the probability of a profit increases, so we raise our bets. But in this game the probability is not affected by previous results and always remains at 60%.

Suppose that we bet a certain percent of our capital and record the current capital after each trade. Repeat the 100-trades sequence again and again, and after a lot (1000 or so) series we'll be able to estimate the distribution of results. Evidently, we'll have different end profits, since the game is random-based. This is called Monte Carlo modeling.

Let us arrange the 1000 profit performances from 1000 series from smaller to larger. Then let us divide this range into 100 parts with equal number of variants in each - so every such a percentile will have 10 variants of performance. The first percentile will contain 10 worst results, and its top limit (number 10) will correspond to what they usually formulate as: "In 1% of cases the results will be inferior to… value". Statistically this percentile is called k-1. The border of the 50 percentile (k-50) would correspond to: "In 505 of the cases the result will be inferior to…"

Table 3 displays the outcomes of the 1000 series with different bet sizes in percents of the capital.

With 10% bet for each trade the minimal capital after 100 trades was 181,1$. In 1% of all trades our capital was under $405 (Profit k1). In 50% the trading yielded $4501 and less (Profit k-50). In 95% of cases the end capital was below $22411 (Profit k-95), and, corerespondingly, in 5% of cases the end capital was above $22411.

Let us review drawdowns (DD in the table). The drawdown is the difference between the maximal capital and its subsequent minimum before the new maximum is reached. With 10% bets in 50% of the cases the DD was over 48%, in 1% over 78% and the maximal DD was almost 90% of the capital. With bets over 30% of the capital we ape practically doomed to ruin. Once again we remind that this game has a positive expectancy - at win/loss probability 60% to 40% the win size relates to loss size as 1 to 1.

Steve Cohen says that: "the traders' general mistake is taking too large positions in relation to their portfolios. The, when the shares move against them, they are hurt too much to remain in control, they finally either panic or freeze in shock"1.

These examples described the importance of bet size in games with an undetermined outcome. So what is money management? An Internet search with those keywords yielded links to services for personal financial control, advices on handling others' money, how to control risk, on Turtle Trading, etc. According to Van Tharp, money management is NOT:
· a part of system that dictates how much you will lose in a given trade
· a way to exit a profitable trade
· is not diversification
· is not risk control
· is not avoiding risks
· is not a part of a system that maximizes performance
· is not a part of the system that tells where to invest

Money management is a part of a trading system that tells "how much". How many units of investitions should be held at a time? How much risk may be taken?

So, money management is controlling the bet size. Te most radical definition known to us is given by Ryan Jones3: money management is limited to defining what sum from your account should be risked on the next trade. Pay attention that this definition does not list as money management controlling the size of an already open position, which Van tharp allows.

Table2.

% loss102030405060708090
% profit required to recover11,125,042,966,7100150223,3400900


Table3.

Bet sizek-50 DD, %k-99 DD, %Max DD, %Worst profit casek-1 profitk-50 profitk-95 profit
1.005.8713.2518.309009561.21521.426
5.0026.8652.3268.174846542.4015.346
10.0048.4378.3689.491814054.50122.411
15.0064.7792.8197.48712376.58673.936
40.0098.81100.00100.0000783687.933

 

So, we do have a winning strategy - what next?

We can open a brokerage account and bet all our capital with the maximal leverage.

Here the most important thing - the money management begins. To clear the situation here is a pair of facts. Ralph Vince invented a game, where bet size was the only moveable parameter. He chose forty doctors of sciences (i.e. not the dumbest people at least) as players, none of which were professional traders or studied statistics. The doctors played a game where 100 random trades were generated, one by one. Every one began at $1000, and before every trade one had to make a single decision - how much (up to 50% of the capital) to bet. 60% of the time the players won their bet, and 40% of the time they lost their bet. This game has an expectancy of 20 cents per dollar risked, i.e. in the long run the player can receive 1 dollar 20 cents per dollar. The academicals made their 100 bets, enough to resolve the expectancy. Making the same trades, they finished the game with different results. Guess how much of them increased their starting capital? Two of forty. 95% of doctors lost money playing a game with a positive expectation!1

Van Tharp made an even more striking example. In an Asian Tour for Dow Jones Telerate TAG (Technical Analysis Group) he gave lectures in 8 cities before 50-100 listeners each time, most of them professional traders for large companies or banks that traded shares, bonds or exchange rates on Forex. In an analogous game over a half of highly professional traders lost!2 Another personal example - a trader offered a similar game to a friend employed by Charles Schwab as a leading analyst. At the first level the distribution of multiples of R with an expectancy of 0,45 and 60% profitable trades. To get to the second level one had to make 50% profit in 100 trades. The result was "I cannot get to level 2 in a day!"3. In 1991 Brinson, Singer and Beebower published a research of the efficiency of 82 portfolio managers in a 10-year period, which showed that 91,5% of all profit was generated by asset distribution3. The asset distribution meant the division of capital between cash, shares and bonds. Only 8,5% of profit was due to buying and selling the right stocks and bonds at the right time.

Let us play the game described by Vince. If there was no risk, i.e. we knew the result of each trade beforehand, it would make sense to bet all the capital each time. So every player would have gained $1000 ..(1.2 ^100)=$82,817,974,522.01 .

In reality, if we bet all $1000 on the first trade, we have a 40% risk to lose all at the first attempt. Even if we win and have $2000, betting all on the next trade would be exactly as insane.

Now suppose we bet $200 at a time. So if five first trades are losing, we again lose all. The probability of such an event is small, just over 1%. But are we ready for such a "small" risk, if we can lose all the money? Suppose we lose in the first two trades (16% probability), so we'd lose 40% of the capital. Beginning from the next trade we must gather 67% of profit just ot restore the starting capital. This effect is called "asymmetric leverage"5.

Table 2 shows that loses of over 50% need improbably large profits just to recover; so if we risk relatively large sums and lose our chances to end up wit a profit are negligible.