Your position size is how much of the portfolio one holding takes. Formulas for it exist, but they need numbers nobody knows in advance: how likely the investment is to work, and how badly it could go wrong. A more useful question is about consequences. If this holding fell by half, or went to zero, what would that do to the whole — and would you hold your nerve?
Some investors write the answer down as a target weight — the share they intend each holding to have — and a maximum weight they'll trim back to if it grows past it. Both are personal. A larger cap lets a winner run and makes one mistake more expensive; a smaller one does the reverse. The app doesn't set limits for single holdings, though the health score marks a portfolio down as its largest holdings grow. It shows each holding's current weight, in its detail view and a Pie Chart of your stock portfolio, so you can compare it with your own rule.
Illustrative sizes. The same fall in a 2% position costs the portfolio 1%.
Educational content only. It is not personal financial advice.