The Avoidable Mistake of Cherry Picking Data


Discussing investments with others is often a minefield of competing information.  Two highly educated people can look at the exact same numbers and come to completely different conclusions about the results.  Information from primary sources even as reputable as Vanguard does not necessarily make the situation any better, as the same fund can appear wonderful in one tool but disappointing in another.  How on earth can an everyday investor find an appropriate portfolio when even the experts can’t agree on what is good and what is not?

The important takeaway is not that risk and returns are unknowable or that everyone who disagrees with you is bad at math.  The problem most often arises from the natural desire of humans to reduce complex problems down to a single straightforward number.  The real world is more complex than most people understand, and the assumptions by which they derive that number can greatly affect the results.  Whether they realize it or not, most investors — casual and professional alike — cherry pick data every day.

Coffee, Stocks, and the Importance of Being Specific

Coffee, Stocks, and the Importance of Being Specific


Everyone loves a good cup of coffee.  It’s one of the most popular beverages in the world, and if one were to poll a random group of passers-by on the street it’s very likely they’d find a good percentage of people who identify as frequent coffee drinkers.  But offer those biggest fans a free cup of home-brewed coffee, and there’s no guarantee they’ll like it.  While people often talk about coffee in universal terms, everyone has a specific type and combination of ingredients that they like best and a caramel macchiato with extra foam tastes much different than a strong coffee served black. The devil is in the details.

Stocks are kind of like coffee in that regard.  Lots of people love them and sing their praises, but that doesn’t mean that all types of stocks are equally appealing to all people.  Walking into a fancy coffee shop with a big menu and just asking for “coffee” may not necessarily yield the results you will like, and walking into your brokerage and announcing “I’d like some stocks, please” might elicit a few funny looks.  What types of stocks?  The ones you choose may drastically change your portfolio outcome, and lumping them all together as a single homogeneous entity sorta misses the point.  In coffee and in stocks, it’s important to be specific.

How to Build a Portfolio One Brick at a Time

How to Build a Portfolio One Asset at a Time


My single favorite toy as a child really wasn’t a single toy.  It was my giant bucket of LEGO accumulated over many years.  The beauty of LEGO is that the combinations are absolutely limitless and the things you can build with them are constrained only by your imagination.  Well… and access to all the right pieces.

You see, when building a spaceship, race car, or castle it’s sometimes not good enough to have a big bucket of parts.  You need to have the right parts.  The right color for the walls, the right size to fit in a tight space, or the right shape to make a respectable wheel or wing.  Many hours were spent browsing the toy aisle not for the final product pictured on the box, but for just the right part in the kit to add to my collection.  Without the right building blocks, the best designs just aren’t the same.

For a while now Portfolio Charts has been focused on the LEGO kits — the portfolios that you can build for yourself and the calculators to help you do it.  But I’ve known for a while that it’s been missing an important ingredient.  Today I’m happy to unveil brand new section to the site dedicated to the portfolio building blocks themselves — Assets.

How Averages Lie


Perhaps the perennial top rated roller coaster in the United States is Millennium Force at Cedar Point in Sandusky, Ohio.  With a max drop of 300ft at 80 degrees and a top speed of 93mph, reviews are predictably glowing and full of adrenaline.


“Best ride in the world!! It’s so fun, you feel like you’re flying.”


“The best ride there! So fast, so extreme, amazing drop. No matter how long the line is make sure you go on the ride.”


Just as interesting to me is a stat you won’t find.  At a length of 6595 ft and a duration of 2:20  from start to finish, the average speed of the coaster is a pedestrian 32mph and would be considered safe in your home neighborhood.  If some robotic fan only judged amusement park rides by average speed, the drive there would blow it out of the water.  And a grandmother picturing a smooth leisurely ride would be in for a very rude awakening.  Clearly, averages don’t tell the whole story.

So why is it that when discussing investing people love to reduce portfolio performance down to a single long-term average?  Just like discussing roller coasters only in terms of averages, that masks the entire experience of the ride!