Reflexivity

投機奇才"George Soros"一直以來以"Reflexivity"來形容金融市場的週期性活動, 當然這亦是他多年投資獲利所根據的基本哲學.

長話短說,"Reflexivity"亦即是指出人類總是帶有知覺(看法),而他們跟據看法而作出的買賣往往會影響資產價格.當向上的看法變成主導時,資產價格自然向上,更有趣的是資產價格的變化亦會間接影響公司的基本面因素(Fundamental Factors; e.g. 盈利'資產值等等)增長,而再度影響資產價格.因此一個"自我強化的循環 (Self-reinforcing feedback loops)"便不斷發生.

那麼這是否表示資產價格只會朝著同一個方向走動(例如向上),這是沒有可能的,原因是"自我強化的循環"的因素亦有耗盡的時侯(或者是無法維持下去),便會掉頭走(向下),而開始一個反向的"自我強化的循環".這亦表達為何金融市場會不斷出現上升和下跌的週期.

從高一個層次看,我們大可以以古今中外的智慧去解釋上述的一切:

1) "資產價格"和"基本面因素"的互動 ---> 佛家所指的萬物相依性
2) 資產價格(經濟)不斷進行的"擴張"和"收縮"的週期交替(反向) ---> 道家所指的物極必反
3) 這個世界並沒有所謂的絕對客觀的價值,很多事倩都是相對性的

這亦暗示,假設金融市場和經濟永遠只會向上而不作定期回顧(Review)是極為不設實際和危險的做法.

複利息向上倍增長的力量固然是大,但別忘記向上的因素耗盡後所行走的收縮反向力亦是同樣大和可怕.正如太極圖內的陰陽一樣,對立的能量永遠是對等和守恆的(亦即Conservation of Energy)

這亦指出一個道理: There is no free lunch!!!


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REFLEXIVITY AND BUBBLES by George Soros (Source: Reuters)
Soros outlined his theory of price formation, and how bubbles inflate and collapse, in a brilliant book on “The Alchemy of Finance”, first published in 1987, but updated in 2003. It remains one of the clearest, most incisive explanations of how and why bubbles occur, and shows how profiting from the “madness of crowds” has been pivotal to his success.

In particular, Soros rejected the prevailing idea that “market prices are … passive reflections of the underlying fundamentals”, a dogma he dismissed as market fundamentalism, or that there were stabilizing forces which would automatically drive prices back towards equilibrium.

Instead, Soros propounded a theory of “reflexivity”, in which fundamentals shape perceptions and prices, but prices and perceptions also shape fundamentals. Instead of a one-way, linear relationship in which causality flows from fundamentals to prices and perceptions, Soros developed the theory of a loop in which prices, fundamentals and perceptions all act on one another.

“I contend that financial markets are always wrong in the sense that they operate with a prevailing bias, but that the bias can actually validate itself by influencing not only market prices but also the fundamentals that market prices are supposed to reflect”.

Later he writes more bluntly: “[The efficient market hypothesis and theory of rational expectations] claims that the markets are always right; my proposition is that markets are almost always wrong but often they can validate themselves”.

Beyond a certain point, self-reinforcing feedback loops become unsustainable. But in the meantime positive feedback causes bubbles to inflate further and for longer than anyone could have foreseen at the outset.

“Typically, a self-reinforcing process undergoes orderly corrections in the early stages, and, if it survives them, the bias tends to be reinforced, and is less easily shaken. When the process is advanced, corrections become scarcer and the danger of a climactic reversal greater”.