Since 2016, interest rates on ten-year Japanese government bonds have been locked in a very tight range, near zero percent. But Japan's central bank could soon change that, and that seemingly small adjustment could create large ripples around the world's financial markets.

This yield curve control in Japan is what we are calling an economic 'butterfly effect,' with billions of dollars at stake.

Music by Drop Electric. Find us: Twitter / Facebook / Newsletter.

Subscribe to our show on Apple Podcasts, Spotify, Pocket Casts and NPR One.

For sponsor-free episodes of The Indicator from Planet Money, subscribe to Planet Money+ via Apple Podcasts or at plus.npr.org.