We Grew Active Deposit Share From 27% to 40% — Then Growth Stalled

A product post-mortem on growing CoinHold, EMCD's crypto savings product. Before any growth work, we spent ~6 months refactoring a legacy codebase that miscalculated accruals — you can't grow a deposit product on rails that break. The biggest lever was uniquely ours: auto-routing mining rewards straight into deposits, which moved active deposit share from 27% to 40% (an OKR I owned, 2x the target). A profit calculator and a full UX redesign lifted average deposit from $4,200 to $5,000. Then activation tactics hit diminishing returns. Phase two isn't more depositors — it's deeper ones: balance-based rates, recurring top-ups as a habit, and savings goals. Behavior, not rate, is the moat.