This is Planet Money from NPR.

Recently, J.P. Morgan Chase launched a new financial metric.

It's called the Volphefi Index.

That name is a mashup of two words, volatility and Caffefi.

Caffefi, I guess, is not technically a word.

It's a famous typo, President Trump made this typo on Twitter a while back.

And this new Volphefi Index measures how much President Trump's tweets affect volatility

in the bond market.

So this is the world we're living in now, where this is a thing.

And we have been living in this world for a while now.

In fact, in 2017, we did our own investing project based on the President's tweets.

Today, we are going to rerun the show from when we launched that project, and then at

the end we'll have an update with new data.

So here's the show from April 2017.

Last week, the biggest investment firm in the world laid off a bunch of its top stock

pickers and replaced them with computer programs.

This is happening all over Wall Street.

Firms are moving away from having humans decide what stocks to buy and sell, and towards

having humans program computers and then letting the computers decide what to buy and sell.

Computers are cheaper than humans.

They are more disciplined, they can think about more things at once, like they can scan

Facebook for trends, they can count the number of cars and Walmart parking lots, and then

...