Abstract: A method of predicting a future balance of an account involves obtaining an initial balance of the account at the first time, and a stochastic projection model that was developed based on a set of prior transactions associated with the account. The stochastic projection model may model past financial transaction data associated with the account as Geometric Brownian Motion, for example. Based on the stochastic projection model, the method involves estimating a future account balance, or a range of potential account balances within a confidence threshold. The predicted future account balance may be used to detect overspending events, indicate whether or not a user can afford to make a particular purchase, and/or otherwise inform an entity the extent of likely future spending.