It has been a great environment for Dynex to build on our solid track record of industry-leading performance as you can see on Slide 12, including the 21% cumulative shareholder total return since December 2019.
We're in a unique moment in history, and we believe every asset management team around the globe will be challenged by unforeseen surprises as we have already continually witnessed over the past 22 months.
For the third quarter, we reported comprehensive income of $0.09 per common share and a total economic return of $0.06 per common share or 0.3% for the quarter.
We also reported earnings available for distribution of $0.54 per common share, a 6% increase over last quarter and well in excess of our $0.39 quarterly common stock dividend.
On a year-to-date basis, through the third quarter, we have paid $1.17 in dividends.
Book value per common share declined modestly to $18.42 from $18.75 or 1.8%, primarily from economic losses on the investment portfolio, principally in lower coupons relative to our hedge position.
First, our earning asset yields improved 3 basis points while overall repo borrowing costs were down another 3 basis points.
Agency RMBS prepayment fees were 11.3 CPR versus 19 flat CPR in the second quarter.
Secondly, TBA dropped income contribution improved by 5 basis points primarily from continued dollar roll specialness during the quarter.
The funding cost benefit on dollar rolls versus repo and RMBS was approximately 60 basis points during the third quarter versus 49 basis points last quarter.
Together, these items drove 4 basis point increase in our adjusted net interest spread to 2.1% for the quarter.
Offsetting these items was an increase in G&A expense of approximately $800,000.
From a portfolio perspective, from quarter to quarter, we reduced our investment portfolio, including TBAs by approximately $500 million, mostly through reducing our investment in TBA, 2.5 [Phonetic].
This occurred toward the end of the quarter and resulted in adjusted leverage declining by nearly a full turn to 5.9 times at the end of the quarter.
As noted on Slide 23, our investment portfolio is approximately $4.8 billion at September 30, with $4.3 billion invested in agency RMBS and TBAs.
The overall notional balance of our hedges at September 30 was $4.3 billion as indicated on Slide 19 with the bulk of the hedges protecting book value from increases in rates in the long end of the curve.
Overall, total shareholders capital grew approximately $18 million during the quarter, which includes approximately $28 million in new common equity raise at the market offerings in the quarter.
Year-to-date, we have raised approximately $224 million in new capital at a gross price before commissions of $18.80.
Our market capitalization adjusted for all shares outstanding is $650 million today versus $420 million at the beginning of the year, substantially increasing the liquidity of our stock for our shareholders while at the same time, unlocking the operating leverage in our business.
Our stock price is virtually unchanged year-to-date and our total shareholder return for 2021 is 6.9% through yesterday.
During the quarter, the 10-year treasury yield touched a low of 1.13% twice and ended the quarter virtually unchanged at 1.46% with a 44 basis point intra-quarter trading range.
Book value on September 30 was at $18.42 and thus far as of October 22nd, book value is up between 2% to 2.5%.
Leverage at the end of the quarter stood at 5.9 times, down from 6.4 times at the beginning of the quarter.
With the recovery in book value quarter to date, leverage stands at 5.6 times and the liquidity position is over $500 million.
I must point out that the levels of inflation that we are experiencing and inflation expectations are among the highest in the last 20 years.
On Slide 20, our weighted average contractual days to maturity of our repo book was about 169 days at September 30, as we targeted longer tenure for our roles between three months and 12 months.
Roughly 50% of the book had a contractual maturity that fell in the six to 12-month range.
There are more public non-bank mortgage companies, subject to quarterly profit metrics now than any other time in the last 20 years.
With this backdrop, we believe agency RMBS spreads could wipe up to 10 basis points to 20 basis points as the taper begins to be implemented, but we think this is more likely to happen during bouts of volatility.
We expect to make an initial adjustment in leverage back up to eight times and when appropriate up to 10 times.
Book value is higher versus quarter end by 2% to 2.5%.
Specifically, we are entering the next few months with over $500 million in liquidity, almost an all-time high for Dynex relatively low leverage of 5.6 times that puts us in a solid position to navigate the environment and limits the risk to the existing portfolio.
We have dry powder for at least three turns and up to five turns of leverage each turn of leverage invested at 11% return adds roughly 1% or $0.24 per share incremental return annually.
This is a significant upside to the 9% dividend yield on our common shares that are trading somewhere between 94% and 95% of book value today.
We've encountered and navigated every market environment for 33 years.
Today, we are building a resilient organization to last the next 33 years and beyond.

Summary:
For the third quarter, we reported comprehensive income of $0.09 per common share and a total economic return of $0.06 per common share or 0.3% for the quarter.