For the six months of 2021, we successfully refinanced 12 legacy CIM securitizations supporting more than $5.6 billion of loans.
The results of these transactions has lowered our overall cost of debt by approximately 245 basis points, and we expect this cost savings to continue to benefit our shareholders in the future.
The National Association of REALTORS recently reported sales of existing homes at 5.9 million annual units, with a median sale price of more than $363,000, up more than 23% from a year ago.
The 30-plus day delinquency rate was reported at 4.4% of outstanding loans, down 42% on a year-over-year basis.
Over the period, the yield on 10-year treasury notes fell by 27 basis points while the yield on two-year treasury rose by nine basis points.
Accordingly, the Bloomberg Barclays U.S. Corporate High Yield Index ended the quarter at 3.75%, its lowest yield ever.
As part of our continued call optimization strategy, this quarter, we called and refinanced six CIM legacy deals, representing more than 1.5 billion of loans.
Our April deals, CIM 2021-R3 and NR3 on a combined basis, had a total of 813 million of securitized debt supported by 977 million of loans.
The combined advance rate was 83%, enabling us to extract 125 million of capital while lowering our cost of debt for these loans by 200 basis points to 2.12%.
Chimera retained 164 million of subordinate and IO securities as investments from these deals.
In June, we issued 546 million CIM 2021-R4.
The deal consisted of 464 million securitized debt, representing an 85% advance rate and a 1.97% cost of debt for these loans.
The R4 freed up 98 million of capital and provided cost savings of approximately 180 basis points.
Chimera retained 82 million of subordinate and IO securities as investments.
We have provided additional details on Page 8 of our earnings supplement to further assist you in the analysis of this quarter's CIM securitizations.
We have made meaningful improvements with the average cost of our secured financing for residential credit assets in the second quarter at 3.5%, down from 4.9% at year end.
This quarter, through the combination of prepay penalties received from our Ginnie Mae project loans and early pay downs of non-agency credit, we generated onetime nonrecurring income of 38 million.
We have resecuritized debt supporting 5.6 billion of loans through seven separate securitizations, lowered our cost of securitized debt by over 245 basis points, lowered the cost of our repo credit facilities by 140 basis points since year end, retired high-cost debt and warrants incurred during the pandemic, issued three jumbo prime securitizations totaling 1.2 billion, purchased more than 200 million of high-yielding fix and flip loans and increased our quarterly dividend by 10% to $0.33.
We have successfully refinanced many of our outstanding legacy deals, and we have an additional five deals with 1 billion of unpaid principal balance that are or will become callable over the next six months.
GAAP book value at the end of the second quarter was $11.45 per common share.
GAAP net income for the second quarter was 145 million or $0.60 per share on a fully diluted basis.
Our core earnings for the second quarter was 130 million or $0.54 per share.
Economic net-interest income for the second quarter was 173 million.
The yield on average interest-earning assets was 7% for the second quarter, while our average cost of funds was 2.6%, resulting in a net-interest rate spread of 4.4%.
Total leverage for the second quarter was 3.3 to one, while our recourse leverage ended the quarter at 1.0 to one.
For the quarter, our economic net-interest return on equity was 19%, and our GAAP return on average equity was 18%.
Expenses for the second quarter, excluding servicing fees and transaction expenses, were 15 million, down approximately 3 million from last quarter.

Summary:
GAAP book value at the end of the second quarter was $11.45 per common share.
GAAP net income for the second quarter was 145 million or $0.60 per share on a fully diluted basis.
Our core earnings for the second quarter was 130 million or $0.54 per share.