Behavioural bias: “Averaging down” vs. “averaging up”
Sometimes it makes sense to reflect why one has done something and why not.
In September I increased the Cranswick position to a full position, for Dart however I was hesitant and could not decide to increase .
One doesn’t need to be a genius in order to find out that increasing the Dart position would have been better:
Since mid of September, Dart made 50%, against more or less flat performance for Cranswick. If I look back to September, I think one of the “true” reasons why I didn’t increase Dart was that I would have to “average” up on Dart, as the stock was already 20% up against my purchase price.
For some reason I am much more hesitant to buy at higher prices. So for Cranswick, it was easier to increase the position because I could slightly decrease my average purchase price. Somehow I seem to prefer lowering the percentage loss on a loss position (“averaging down” than to lower the percentage profit of a gain position (“averaging up”).
I am not sure if this fits into the standard behavioural biases, maybe it is a special form of “anchoring”.
This behavioural bias, not increasing the Dart stake cost me around 1% of portfolio performance so far and now I am even more hesitant to buy. It is also in direct contradiction to the fact that “momentum” combined with Value seems to generate strong results in the long run as demonstrated by O’Shaugnessey’s “what works on Wall Street”.
Lessons (hopefully) learned:
In the future I need to have a better formulated plan for scaling into a position in order to avoid this “behavioural bias”. Either a clear timeline or some clear fundamental triggers where I then execute regardless if the position has already increased to a certain extent or not.