Thanks, would be curious to get your thoughts given your experience in this problem space.
Since we lean DIY / prosumer, our thought is to provide options to the user. Around rebalancing, we're exploring a few options: calendar rebalancing, constant-proportion rebalancing, and rebalancing with only new contributions. Then, analytics to make it clear what is a short vs long-term holding.
Right now we're non custodial, we link to existing brokers. We are looking to become a register broker dealer in the next few months. The fractional-heavy model makes it such that it's better for us to vertically integrate.