Margins matter. The more Southwest Gas (NYSE: SWX) keeps of each buck it earns in revenue, the more money it has to invest in growth, fund new strategic plans, or (gasp!) distribute to shareholders. Healthy margins often separate pretenders from the best stocks in the market. That's why we check up on margins at least once a quarter in this series. I'm looking for the absolute numbers, so I can compare them to current and potential competitors, and any trend that may tell me how strong Southwest Gas's competitive position could be.

Here's the current margin snapshot for Southwest Gas over the trailing 12 months: Gross margin is 27.8%, while operating margin is 14.1% and net margin is 6.9%.

Unfortunately, a look at the most recent numbers doesn't tell us much about where Southwest Gas has been, or where it's going. A company with rising gross and operating margins often fuels its growth by increasing demand for its products. If it sells more units while keeping costs in check, its profitability increases. Conversely, a company with gross margins that inch downward over time is often losing out to competition, and possibly engaging in a race to the bottom on prices. If it can't make up for this problem by cutting costs -- and most companies can't -- then both the business and its shares face a decidedly bleak outlook.

Of course, over the short term, the kind of economic shocks we recently experienced can drastically affect a company's profitability. That's why I like to look at five fiscal years' worth of margins, along with the results for the trailing 12 months, the last fiscal year, and last fiscal quarter (LFQ). You can't always reach a hard conclusion about your company's health, but you can better understand what to expect, and what to watch.

Here's the margin picture for Southwest Gas over the past few years.

Source: S&P Capital IQ. Dollar amounts in millions. FY = fiscal year. TTM = trailing 12 months.

Because of seasonality in some businesses, the numbers for the last period on the right -- the TTM figures -- aren't always comparable to the FY results preceding them. To compare quarterly margins to their prior-year levels, consult this chart.

Source: S&P Capital IQ. Dollar amounts in millions. FQ = fiscal quarter.

Here's how the stats break down:

  • Over the past five years, gross margin peaked at 27.8% and averaged 24.5%. Operating margin peaked at 14.1% and averaged 12.1%. Net margin peaked at 6.9% and averaged 5.2%.
  • TTM gross margin is 27.8%, 330 basis points better than the five-year average. TTM operating margin is 14.1%, 200 basis points better than the five-year average. TTM net margin is 6.9%, 170 basis points better than the five-year average.

With TTM operating and net margins at a 5-year high, Southwest Gas looks like it's doing great.

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