As an investor, it pays to follow the cash. If you figure out how a company moves its money, you may eventually find some of that cash flowing into your pockets.

In this series, we'll highlight four companies in an industry and compare their "cash king margins" over time, trying to determine which has the greatest likelihood of putting cash back in your pocket. After all, a company can pay dividends and buy back stock only after it's actually received cash -- not just when it books those accounting figments known as "profits."

Today let's look at CME Group (Nasdaq: CME) and three of its peers.

The cash king margin
Looking at a company's cash flow statement can help you determine whether its free cash flow actually backs up its reported profit. Companies that can create 10% or more free cash flow from their revenue can be powerful compounding machines for your portfolio. A sustained high cash-king margin can be a good predictor of long-term stock returns.

To find the cash king margin, divide the free cash flow from the cash flow statement by sales:

Cash king margin = Free cash flow / sales

Let's take McDonald's as an example. In the four quarters ending in December, the restaurateur generated $7.15 billion in operating cash flow. It invested about $2.73 billion in property, plant, and equipment. To calculate free cash flow, subtract McDonald's investment ($2.73 billion) from its operating cash flow ($7.15 billion). That leaves us with $4.42 billion in free cash flow, which the company can save for future expenditures or distribute to shareholders.

Taking McDonald's sales of $27.0 billion over the same period, we can figure that the company has a cash king margin of about 16.4% -- a nice high number. In other words, for every dollar of sales, McDonald's produces more than $0.16 in free cash.

Ideally, we'd like to see the cash king margin top 10%. The best blue chips can notch numbers greater than 20%, making them true cash dynamos. But some businesses, including many types of retailing, just can't sustain such margins.

We're also looking for companies that can consistently increase their margins over time, which indicates that their competitive position is improving. Erratic swings in margins could signal a deteriorating business, or perhaps some financial skullduggery; you'll have to dig deeper to discover the reason.

Four companies
Here are the cash king margins for four industry peers over a few periods:


Cash King Margin (TTM)

1 Year Ago

3 Years Ago

5 Years Ago

CME Group 35.8% 39.8% 38.9% 35.2%
NYSE Euronext (NYSE: NYX) 19.9% 6.9% 8.4% 7%
Nasdaq OMX Group 16.9% 12.4% 4.4% 10.9%
CBOE Holdings 34.2% 25.5% 29.1% NA

Source: S&P Capital IQ. TTM = trailing 12 months.

These are strong numbers all around. All of these companies meet our 10% threshold for attractiveness, with CME Group and CBOE Holdings offering more than triple that standard. NYSE Euronext offers nearly double our desired 10% and has grown its margins more than 10 percentage points from five years ago. Nasdaq OMX Group is a few percentage points behind, but it has grown its cash king margins 6 percentage points from five years ago. Compare these returns to the blue chips of software and biotech to get perspective.

CME Group runs a futures exchange and clearinghouse that gains most of its business from interest-rate and stock futures and hard commodities. While CME's involvement in the MF Global scandal has cost the company money and hurt its reputation, the company claims that it has still managed to take market share from competitors NYSE Euronext and IntercontinentalExchange (NYSE: ICE). Also, CME stands to gain from increased investor interest in non-traditional investments, which could allow the company to grow.

The cash king margin can help you find highly profitable businesses, but it should only be the start of your search. The ratio has its limits, especially for fast-growing small businesses. Many such companies reinvest all of their cash flow into growing the business, leaving them little or no free cash -- but that doesn't necessarily make them poor investments. Conversely, the formula works better for slower-growing blue chips. You'll need to look closer to determine exactly how a company is using its cash.

Still, if you can cut through the earnings headlines to follow the cash instead, you might be on the path toward seriously great investments.

Want to read more about CME Group? Add it to My Watchlist, which will find all of our Foolish analysis on this stock.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.