Richard Thomas
Analyst · Sterne Agee
Thanks, Chris. Good morning, everyone. Our effective tax rate was 34.4% for the 6 months ended June 30, 2012, compared with 33.8% for the first quarter. This increase was due to higher taxable income related to current earnings trends. Overall, our effective tax rate is estimated, and may fluctuate, based upon the ratio of taxable income to total income considering tax advantaged municipal bond income and nondeductible expenses.
Now, turning to our investment portfolio. During the second quarter of 2012, we provided an average of approximately $256.9 million in overnight funds to the Federal Reserve and received approximately 25 basis points on collected balances. We also maintained about $60 million in short-term CDs and money markets with other financial institutions, yielding approximately 67 basis points.
At June 30, 2012, our available-for-sale investment securities totaled $2.3 billion, down $113.2 million from March 31, 2012. Investment securities currently represent approximately 35% of our total assets. Our available-for-sale investment portfolio continued to perform well. At June 30, 2012, we had an unrealized gain of $75.1 million, up from $71.4 million for the prior quarter. Firstly, all our mortgage-backed securities are issued by Freddie Mac or Fannie Mae, which have the implied guarantee of the U.S. government. We have 6 private label mortgage-backed issues, totaling a relatively modest $3.4 million.
We continue to strategically reinvest our cash flow from our investment portfolio, carefully weighing current rates and overall interest rate risks. During the second quarter, we purchased only $30.9 million in mortgage-backed securities as our average yield was only 1.6%. We attempt to maintain a neutral position at the short end of the treasury curve by reinvesting in mortgage-backed securities with an average duration of under 5 years, to avoid material expansion risk as interest rates may rise in the future. We also purchased $6.5 million in municipal securities with an average tax equivalent yield of 3.17%. Money-backed qualified municipal securities, that meet our investment criteria, remains challenging but still desirable. At the end of the second quarter, we held $1.58 billion in mortgage-backed securities, and $634.9 million in municipal securities. Combined, these represent 98% of our $2.3 billion investment portfolio.
Now turning to our capital position. Our capital ratios are well above regulatory standards and remain above our peer group average. Our June 30, 2012 capital ratios will be released soon, concurrently with our second quarter Form 10-Q.
Shareholders’ equity increased by $18.3 million to $748.3 million for the second quarter. This increase is attributable to retained profits of $23.6 million an increase in unrealized gain-on-investment securities of $2.2 million, and $1.4 million for various stock-based compensation items, partially offset by $8.9 million in cash dividends.
Effective June 17, 2012, we redeemed 50% of the trust preferred securities in CVB Statutory Trust I. We paid approximately $20 million for this redemption, and this will save us about $664,000 annually.
I will return the call back to Chris for his closing remarks.