How is the interest rate of the SBLOC determined?

Betterment only supports variable-rate lines of credit at this time.

The Bancorp’s SBLOC rates are based on the Wall Street Journal (WSJ) US Prime Rate plus or minus a spread determined by The Bancorp, which varies depending on the credit limit a client is approved for (the higher the credit limit, a greater the rate discount). Interest rates are adjusted monthly.

Interest is only charged on the balance you have drawn from the SBLOC, but the applicable interest rate is based on the size of the total approved credit line.