Anyone can invest in any public index. We do have private indexes too (this is a premium feature, where we charge a subscription), wherein only folks you share your index with can view and invest. You can also "nest" others' indexes in your indexes (e.g. https://enombic.com/aml/autopilot).

We don't surface a lot around how much you invest right now, as there are some privacy concerns. But, depending on how things evolve it may be something we enable.