Asset Sales and TBA Eligible Securities
We maintain a portfolio of highly liquid mortgage-backed securities. We may sell our agency securities through the TBA market by delivering them into TBA contracts, subject to "good delivery" provisions promulgated by the Securities Industry and Financial Markets Association ("SIFMA"). We may alternatively sell agency securities that have more unique attributes on a specified basis when such securities trade at a premium over generic TBA securities or if the securities are not otherwise eligible for TBA delivery. Since the TBA market is the second most liquid market (second to the U.S. Treasury market), maintaining a significant level of agency securities eligible for TBA delivery enhances our liquidity profile and provides price support for our TBA eligible securities at or above generic TBA prices. As of September 30, 2015, approximately 91% of our fixed rate agency MBS portfolio was eligible for TBA delivery.
To the extent we raise additional equity capital through follow-on equity offerings, through our at-the-market offering program or under our dividend reinvestment and direct stock purchase plan, we may use cash proceeds from such transactions to purchase additional investment securities, to make scheduled payments of principal and interest on our repurchase agreements and for other general corporate purposes. There can be no assurance, however, that we will be able to raise additional equity capital at any particular time or on any particular terms.
Common Stock Repurchase Program
Our Board of Directors adopted a program that authorizes repurchases of our common stock up to a specified amount. In October 2015, our Board of Directors extended its authorization through December 31, 2016. Shares of our common stock may be purchased in the open market, including through block purchases, or through privately negotiated transactions, or pursuant to any trading plan that may be adopted in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended. The timing, manner, price and amount of any repurchases will be determined at our discretion and the program may be suspended, terminated or modified at any time for any reason. Among other factors, we intend to only consider repurchasing shares of our common stock when the purchase price is less than our estimate of our current net asset value per common share. Generally, when we repurchase our common stock at a discount to our net asset value, the net asset value of our remaining shares of common stock outstanding increases. In addition, we do not intend to repurchase any shares from directors, officers or other affiliates. The program does not obligate us to acquire any specific number of shares, and all repurchases will be made in accordance with Rule 10b-18, which sets certain restrictions on the method, timing, price and volume of stock repurchases.
During the three and nine months ended September 30, 2015, we repurchased approximately 2.4 million and 6.3 million shares, respectively, of our common stock at an average repurchase price of $19.08 and $19.57 per share, respectively, including expenses, totaling $45 million and $124 million, respectively. As of September 30, 2015, the total remaining amount authorized for repurchases of our common stock was $868 million.
Off-Balance Sheet Arrangements
As of September 30, 2015, we did not maintain any relationships with unconsolidated entities or financial partnerships, such as entities often referred to as structured finance, or special purpose or variable interest entities, established for the purpose of facilitating off-balance sheet arrangements or other contractually narrow or limited purposes. Further, as of September 30, 2015, we had not guaranteed any obligations of unconsolidated entities or entered into any commitment or intent to provide funding to any such entities.
This document contains "forward-looking statements" (within the meaning of the Private Securities Litigation Reform Act of 1995) that inherently involve risks and uncertainties. Our actual results and liquidity can differ materially from those anticipated in these forward-looking statements because of changes in the level and composition of our investments and other factors. These factors may include, but are not limited to, changes in general economic conditions, the availability of suitable investments from both an investment return and regulatory perspective, the availability of new investment capital, fluctuations in interest rates and levels of mortgage prepayments, deterioration in credit quality and ratings, the effectiveness of risk management strategies, the impact of leverage, liquidity of secondary markets and credit markets, increases in costs and other general competitive factors.