When Jamie Dimon bought his first stock as a teenager, he could scarcely have imagined that, half a century later, his core investment lesson—don’t blow up—would underpin the risk culture of the world ...

Dimon’s introduction to the world of markets was guided by his father, a stockbroker. At just age 14 in 1972, Dimon purchased his first stock, only to watch the market nosedive by 45% within two years ...