effected) on the available-for-sale portfolio totaled $0.7 million as of September 30, 2024, compared to $16.6 million as of June 30, 2024. Unrecognized losses (tax-effected) on the held-to-maturity portfolio totaled $41.8 million as of September 30, 2024, compared to $56.4 million as of June 30, 2024. Combined unrealized and unrecognized losses (tax-effected) on the available-for-sale and held-to-maturity portfolios totaled $42.5 million, or 2.08% of the combined portfolios as of September 30, 2024, compared to $73.0 million or 3.91% of the combined portfolios as of June 30, 2024. The decrease in unrealized and unrecognized losses (tax-effected) was largely driven by the fall in the 10-year Treasury yield which is the benchmark that agency mortgage-backed securities follow. The 10-year Treasury yield fell 62 basis points to 3.78% as of September 30, 2024, compared to 4.40% as of June 30, 2024.
Investment securities portfolio average yield was 4.06% in the quarter, compared to 4.00% in the prior quarter and 3.24% in the third quarter of 2023.
Deposits and Borrowings
Deposits were $10.3 billion as of September 30, 2024, compared to $10.8 billion as of June 30, 2024, and September 30, 2023. Noninterest-bearing demand deposits accounted for 21% of total deposits as of September 30, 2024, compared to 20% and 22% as of June 30, 2024, and September 30, 2023, respectively. Certificates of deposit accounted for 25% of total deposits as of September 30, 2024, compared to 26% and 28% as of June 30, 2024, and September 30, 2023, respectively. Core deposits accounted for 64% of total deposits as of September 30, 2024, compared to 62% and 68% as of June 30, 2024, and September 30, 2023, respectively. Brokered deposits accounted for 36% of total deposits as of September 30, 2024, compared to 38% and 32% as of June 30, 2024, and September 30, 2023, respectively.
Cost of deposits was 3.41% for the quarter, compared to 3.49% for the prior quarter and 3.03% for the third quarter of 2023.
Insured and collateralized deposits accounted for approximately 85% of total deposits as of September 30, 2024, relatively unchanged from the prior quarter.
Our loan to deposit ratio measured 95.9% as of September 30, 2024, compared to 93.8% and 95.1% as of June 30, 2024, and September 30, 2023, respectively. The increase was largely due to a decrease in wholesale deposits.
Borrowings were $1.7 billion as of September 30, 2024, compared to $1.7 billion and $984 million as of June 30, 2024, and September 30, 2023, respectively. Average borrowings outstanding were $1.7 billion or 12.6% of total average assets for the quarter, compared to $1.4 billion or 10.4% of total average assets for the prior quarter and $0.6 billion or 4.5% for the third quarter of 2023. The weighted average rate paid on borrowings was 4.04% for the quarter, compared to 4.12% for the prior quarter and 4.16% for the third quarter of 2023. Borrowings include $266.6 million in borrowings from the Bank Term Funding Program (“BTFP”) at the Federal Reserve Bank at a rate of 4.76%, which will mature in January 2025.
As of September 30, 2024, our unused borrowing capacity was $2.9 billion, which consists of available lines of credit with FHLB and other correspondent banks as well as access to the Federal Reserve Bank’s discount window.
Private Wealth Management and Trust Assets
Our AUM balance was $5.5 billion as of September 30, 2024, relatively unchanged from the prior quarter, and compared to $5.0 billion as of September 30, 2023. Activity within the AUM balance during the quarter consisted of the following: $38 million of new accounts; $194 million of net withdrawals; and $167 million of performance