Good question, we of course need revenue to serve our customers and grow. The short answer is that brokerages can make money from the assets held in their accounts and from handling customer trades. And compared to legacy brokerages, being digital-first allows M1 to minimize costs and offer our investing service without commission fees.

Our founder and CEO goes into more detail about our sources of revenue in this blog post: https://blog.m1finance.com/m1-is-now-free/. (Look for the section "How We’ll Make Money".)