Why is the share count I see during trade review just an estimate?

The price shown during trade review is an estimate based on delayed market data. Your actual execution price may differ, since Betterment executes trades during the next available trading window.

Because of this, the final price you receive will reflect market conditions at the time your order is executed, which may be higher or lower than what you saw during review. While we can’t guarantee an exact price in advance, our trading system is designed to seek the best price reasonably available based on market conditions at the time of execution.