Quarter-end book value was $12.32 per common share, up $0.58 from Q3 2020.
As of the close of business last Friday, February 12, we estimate book value to be approximately $12.90 per common share ex dividend.
ARMOUR's Q4 comprehensive income was $60.2 million or $0.89 per common share.
We paid dividends of $0.10 per common share for each month in the fourth quarter for a total of $19.6 million.
We've also declared February and March common dividends at the rate of $0.10 per share and Series C preferred stock dividends for Q1 at the rate of $0.14583 per share.
Echoing the positive market sentiment, repo financing also improved over the quarter, dropping from 20 to 25 basis points in the third quarter for 30-day tenors, down to 15 to 20 basis points currently.
The flip side of all the good news is that historically low mortgage rates helped create the largest wave of home for loan refinancing since 2003.
While we do allocate approximately 36% of our portfolio to dollar rolls in 30-year and 15-year TBAs, 94% of the remaining portfolio are assets with favorable prepayment protection characteristics, including prepayment penalties, lower loan balances and seasoning.
The average CPR in our portfolio was 17.3% as of the fourth quarter versus 16% in the third quarter, which were both significantly below the aggregate speeds on more generic MBS.
Year-to-date, the portfolio is averaging 17.9% CPR.
This is reflected in our implied leverage ratio of 7.7 at the end of the fourth quarter and 6.9 implied leverage ratio currently.
ARMOUR's duration as of year-end was 0.62 and is currently 0.76.
It should be noted that a significant portion of the portfolio's duration is in the key rate buckets of inside three years, where we expect yields to be pegged close to 0 for the foreseeable future.

Summary:
ARMOUR's Q4 comprehensive income was $60.2 million or $0.89 per common share.