Monday, May 03, 2010

Core Ideas in Trading Psychology: Market Structure and Adapting to Market Change

A key idea running through the TraderFeed blog as well as my books on trading psychology is that markets play out the same patterns as people: they exhibit particular states, provide markers for when they are shifting those states, and change their behavior when transitioning to new states. (See The Psychology of Trading for a detailed presentation of states and state shifts).

The states exhibited by markets are range modes (periods in which value is established in a relatively narrow band of prices and price does not move far from this value area) and trending modes (periods in which value is established at successively higher or lower price levels until fresh supply or demand from longer time frame participants enters the market and creates a range equilibrium). Every market state can be described as a joint function of directional tendency and volatility. Thus we can have volatile and non-volatile range markets, and we can have volatile and non-volatile trending markets.

Because markets change states at multiple time frames, the time series of price changes in markets is non-stationary. That means that the mean price change (direction) and standard deviation of price changes (volatility) in one period can vary significantly from those in the next period. If we think of price movement as generated by a process, then non-stationarity means that there is not a single, unchanging process generating all price changes. Markets, like people, display "multiple personalities": they behave differently when occupying different states.

Many of the market patterns described by technical analysts, including breakouts, double tops and bottoms, etc., represent transitions from one state to another. Some of the best profit opportunities occur in markets when traders behave like psychologists: reading patterns and transitions and timing actions accordingly.

A major reason that traders do not succeed is that they fail to read market structure--the states that markets are in--and thus are not sensitive to the shifts in structure that mark transitions between trending and non-trending modes. This leaves traders placing stop loss points and profit targets at levels that do not reflect the market's most recent levels of directionality and volatility.

Skilled, experienced traders learn to sense shifts in market states and thus recognize when trends are slowing down and turning into periods of consolidation; when range markets are heating up and ready to break out. When new participants enter the market and influence the pace of state change, as in the case of algorithmic trading occurring at short time frames, this can disrupt the implicit learning and pattern recognition of even those skilled traders, necessitating new periods of observation and internalization of patterns.

Failure to restrain risk during such periods of structural change in markets is a major reason why traders who made money consistently during one market epoch fail to sustain success during later periods. The challenge of trading is not only to learn market patterns, but also to adapt to new patterns as the drivers of price change (the themes dominating markets, the participants active in markets) shift over time.

For more on the topic of market structure, see the posts (including links) on Strategies and Tactics in Trading, Calculating Price Targets, and Three Basic Trade Setups.