Definitive Materials Filed by Investment Companies. (497)

Principal Exchange-Traded Funds

Supplement dated March 31, 2020

to the Statement of Additional Information dated November 1, 2019

(as previously supplemented)

This supplement updates information currently in the Statement of Additional Information. Please retain this supplement for future reference.

Delete all references to Principal Portfolio Strategies^SM from the statement of additional information and replace with Principal^® Global Asset Allocation.