Our investment process is both qualitatively and quantitatively intensive. Throughout the course of a year we look at hundreds of companies. Most of them receive only a cursory look – we don’t like the business, the valuation is too stretched, or we simply have no insight into the business. We usually glance at them and move on.
But if we really like the business and/or its valuation, we build a model. Often, just from a cursory look we know that the stock is not cheap enough, but if we really (really!) like the business we’ll invest the time to model it so we can understand it better and set a price at which we want to buy it (and then wait).
We build a lot of models. We built over a hundred models last year (we bought only a handful of stocks). Building models is important for us. Models help us to understand businesses better. They provide insights as to which metrics matter and which don’t. They allow us to stress test the business: we don’t just look at the upside but spend a lot of times looking at the downside – we try to “kill” the business. We usually try to drill down to essential operating metrics. If it is a convenience store retailer, we’ll look into gallons of gas sold and profit per gallon. If it is a driller (see our Helmerich & Payne analysis), we look at utilization rates, rigs in service, average revenue per rig per day, etc.
In the past, when we owned Joseph A. Banks, a model helped us understand the impact maturation of its new stores had on same-store sales (PDF, see slide 49). Half of Joseph A. Banks stores were less than five years old, and their maturation drove significant same-store sales increase for years.
We looked at American Express before the crisis, which gave us insight into inflated profit margins of the financial sector, and thus we avoided for the most part the carnage in the financials. We thought American Express stock was not cheap enough at the time, but we learned that Amex’s high swipe-fee revenue provided an important buffer to help the company absorb significant loan losses. Amex could have withstood over 10% loan losses on its credit card portfolio and still have remained profitable. This insight gave us the confidence to buy Amex during the crisis.
Models are important because they help us remain rational. It is only the matter of time before a stock we own will “blow up” (or, in layman’s terms, decline). We can go back to our model and assess whether the decline is warranted. The model then gives us the confidence to make a rational (very key word) decision: buy more, do nothing, or sell.
Models are frameworks that help us think about the businesses we analyze. We are always aware of John Maynard Keynes’ expression, “I’d rather be vaguely right than precisely wrong.” Models are not a panacea, but they are an important and often invaluable tool. However, models are only as good as their builders and the inputs to them.