Why do some big successful brands go bust?

Toast is back for a new series, taking a look at the decisions that often left investors burnt.

I'm Sean Farrington, a BBC business journalist. I'll be hearing about the hype.

They're going to do the deal that makes them the most money at that point of time.

And I'm picking what went wrong, talking to owners and employees to ask, what can we learn?

It was being undercut by similar rivals. It just couldn't survive.

Toast. Listen first on BBC Sounds.

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 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 Semex, as some people call it.

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

I do 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.

Cement 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.

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