The Company's portfolio consisted of Fannie Mae, Freddie Mac and Ginnie Mae mortgage securities and was valued at $24.3 billion as of March 31, 2013. During the first quarter of 2013, the annualized yield on average assets was 2.33%, and the annualized cost of funds on average liabilities (including realized cost of hedges) was 0.98%, resulting in a net interest spread of 1.35% for the quarter.
The $24.3 billion portfolio of Agency Securities at March 31, 2013 consisted of 92.2% fixed rate Agency Securities and 7.8% ARMs and Hybrid ARMs. The Company defines "Hybrid ARMs" as adjustable rate Agency Securities with longer than 18 months to rate reset and "ARMs" as adjustable Agency Securities with rate resets shorter than 19 months.
Portfolio Financing, Leverage and Interest Rate Hedges
As of March 31, 2013, the Company financed its portfolio with approximately $24.8 billion of borrowings under repurchase agreements. The Company's debt to equity ratio, as measured to paid-in capital, as of March 31, 2013, was 8.85 to 1. The Company's debt-to-total shareholder equity ratio as of March 31, 2013, was 9.17 to 1.
As of March 31, 2013, the following information was available related to the Company's interest rate risk and hedging activities: the Company's repurchase agreements had a weighted-average maturity of approximately 36 days. The Company had a notional amount of $12.3 billion of various maturities of interest rate swap contracts with a weighted average swap rate of 1.4%. The Company had a notional amount of $1.6 billion of various maturities of swaptions with a weighted average swap rate of 2.1%. The Company had a notional amount of $99.0 million of various maturities of Eurodollar futures contracts sold at a weighted average swap equivalent rate of 1.9%.
ARMOUR's management fee is 1.5% (per annum) of gross equity raised up to $1 billion and 0.75% (per annum) of gross equity raised above $1.0 billion. As of March 31, 2013, ARMOUR's effective management fee was 1.01% based on gross equity raised. Economies of scale are achieved as the Company's equity continues to increase.