Here’s something the rich know about managing investment risk that can help you, too

For decades, investors have heard it’s smart to construct a 60/40 stock-bond portfolio. Investors and their financial advisers often tweak asset allocation to reflect a client’s age, risk tolerance and other factors.

Now along comes Larry Fink, chief executive of BlackRock

BLK, the world’s largest asset manager. He recently suggested replacing the traditional 60/40 model with a 50/30/20 split: 50% stocks, 30% bonds and 20% private assets (aka alternative investments).