The LEGO December Effect

I was messing around with some of the data in the price guide and came across something I had recognized before but had never really paid much attention to. As most of you probably know from your LEGO investing experience, December is usually recognized as the best single month in which to sell some of your precious investments. More specifically, this trend seems to affect especially hard the modulars, large scale models and the UCS so I will be focusing on those in this first article.

I selected 18 different and large sets from the themes I mentioned above and that were released before 2010, so most of them have been out of the shelves for around 3 years already. Also, the prices are based on the last 12 months showed on Brickpicker's Price Guide. Let's see some of the results:
 

As you can see above, most of the sets that are part of the themes I mentioned above share the same price drop once the December comes around. Even more, some of the sets above actually experience their lowest price of the whole year during the holidays. There are only a couple of exceptions in the table, so I think it is pretty safe to say that this "December effect" is actually more common than I originally thought.

It is somewhat hard for me to explain this effect other than by checking the number of sold listings over the past 12 months in BP's Price Guide. There is a widespread belief that December is the investor's best bet to maximize profits, so it seems likely that a lot of people just wait to sell during this period and as a consequence increase the supply of the sets. If you actually go ahead a check the number of sold listings, in effect most of the ones in the table present the highest number of sold copies during this month. This is probably one of the major causes for the dip in value most of them experience

Other than that, when I digged a little deeper I noticed that this seems to be the case only with a small number of the popular themes. Some other themes do in fact present a spike in price around the holidays, making the phenomenon a little harder to understand. Price of the sets may also be a factor as the sets from the themes included in the table tend to be the pricier ones, maybe causing the increase in supply to really manifest itself very sharply.

What does this mean for the LEGO investor? well, it would seem that sellers of the themes above should really consider getting rid of their inventory at some other point around the year, otherwise the data seems to suggest they will be taking quite a hit by selling when everyone else is as well.

This short blog article was just a little over the surface kind of analysis, but I felt that it was very important for me to throw it out there and start some level of discussion about the reasons and the validity of this December Effect. I am sure some of you have more insights on this, and I would really like to see your comments.