Some of the most profitable industries in the U.S are not the ones most investors talk about.

Tobacco leads. Software is near the top. Semis stay incredibly strong. Even railroads and utilities rank higher than many would expect.

This is a good reminder that investing is not just about revenue growth.

It is about how much of that revenue actually turns into profit.

High-margin industries tend to have one or more of the following:

• pricing power

• strong competitive advantages

• low incremental costs

• difficult-to-replicate business models

That does not automatically make every company in these industries a buy.

But it does tell you where to look more closely.

Because when a high-quality business in a high-margin industry starts trading at the wrong price, that is often where the best opportunities appear.

Which industry here stands out most to you?