In August 2015, we completed an underwritten public offering of 9,890,000 shares of our common stock at a public offering price of $25.25 per share, of which 5,590,000 shares are subject to forward sale agreements. The forward sale agreements provide us with flexibility to manage our capital based upon sales levels. The net proceeds available to us through physical settlement of the forward sale agreements based on the forward sale price would be approximately $134.6 million. See Note 14 to our audited consolidated financial statements for more information on this offering. We believe our existing statutory capital and surplus, the statutory surplus we expect to generate internally through statutory earnings and the capital raised through the public offering will be sufficient to support continuing strong sales.
We periodically revise the key assumptions used in the calculation of amortization of deferred policy acquisition costs and deferred sales inducements retrospectively through an unlocking process when estimates of current or future gross profits/margins (including the impact of realized investment gains and losses) to be realized from a group of products are revised. The impact of unlocking on our results of operations, including the impact of account balance true ups and adjustments to future period assumptions for interest margins, surrenders and certain expenses, was as follows:
The fair value of the 2015 notes hedges changed based upon changes in the price of our common stock, interest rates, stock price volatility, dividend yield and the time to expiration of the 2015 notes hedges. Similarly, the fair value of the conversion option obligation to the holders of the 2015 notes changed based upon these same factors and the conversion option obligation was accounted for as an embedded derivative liability with changes in fair value reported in the Change in fair value of embedded derivatives. The amount of the change in fair value of the 2015 notes hedges was typically equal to the amount of the change in the related embedded derivative liability and there typically was an offsetting expense in the change in fair value of embedded derivatives. Due to the partial unwind agreements we entered into in 2014, the decrease in the change in the fair value of the 2015 notes embedded derivative conversion liability exceeded the decrease in the fair value of the 2015 notes hedges by $10.1 million for the year ended December 31, 2014. Due to the partial unwind agreements we entered into in 2013, the amount of the change in fair value of the 2015 notes hedges was $3.8 million more than the amount of the change in the related embedded conversion derivative liability for the year ended December 31, 2013. See Note 5 to our audited consolidated financial statements for a discussion of the unwind agreements, the 2015 notes hedges and the 2015 notes embedded derivative conversion liability.
Losses on available for sale fixed maturity securities were realized primarily due to strategies to reposition the fixed maturity security portfolio that resulted in improved net investment income, risk or duration profiles as they pertain to our asset liability management. Corporate securities were sold at losses in 2015 and 2013 due to our long-term fundamental concern with the issuers' ability to meet their future financial obligations. See Note 4 to our audited consolidated financial statements for additional discussion of allowance for credit losses recognized on mortgage loans on real estate.
The independent pricing services provide quoted market prices when available. Quoted prices are not always available due to market inactivity. When quoted market prices are not available, the third parties use yield data and other factors relating to instruments or securities with similar characteristics to determine fair value for securities that are not actively traded. We generally obtain one value from our primary external pricing service. In situations where a price is not available from this service, we may obtain further quotes or prices from additional parties as needed. In addition, for our callable United States Government sponsored agencies we obtain multiple broker quotes and take the average of two broker prices received. Market indices of similar rated asset class spreads are considered for valuations and broker indications of similar securities are compared. Inputs used by the broker include market information, such as yield data and other factors relating to instruments or securities with similar characteristics. Valuations and quotes obtained from third party commercial pricing services are non-binding and do not represent quotes on which one may execute the disposition of the assets.