This is the BBC.

Hello, I'm Wesley Stevenson and this is more or less on the BBC World Service.

Donald Trump's victory in the US elections last year was bad news for many Mexican companies.

When the bell rang to signal the opening of the New York Stock Exchange on November the 9th,

shares in Mexican firms started going south.

If Donald Trump followed through on his promise to build a wall

and renegotiate the North America Free Trade Agreement,

things were going to be tough for these companies.

Since then, some shares have recovered, but most have stayed well below their free election highs.

There's a notable exception, though.

A Mexican firm called SEMEX, or CMEX, or some people call it.

It shares have reached their highest level since the financial crisis.

You have a big rally for the building materials companies,

especially CMEX.

This is the second largest cement company in the world,

interestingly, based out of Mexico.

CMEX is of course a key ingredient in concrete,

and if you were building, say, a great big wall,

perhaps you're going to need tons of the stuff,

and you can't just get it from anywhere.

There are American producers in the region as well,

but because cement and concrete are so heavy,

...