 DES MOINES, Iowa--BUSINESS WIRE--Principal Financial Group announced today May Tong will join Principal Global Asset Allocation 150 billion AUM1, the specialized global asset allocation investment team of Principal Global Investors, as a portfolio manager. Principal has a strong history of implementing research-driven, multi-asset class solutions including the Principal Strategic Asset Management SAM target risk portfolios, the Principal LifeTime target date fund series, and several o 