The amortized cost and fair value of debt securities classified as available-for-sale at September 30, 2021 and December 31, 2020 were as follows:

(a) Certain hybrid instruments possessing characteristics typically associated with debt obligations.

The Company’s investment securities are classified as available for sale. Agency bonds and notes, SBA guaranteed loan certificates, residential and commercial agency mortgage-backed securities, and agency collateralized mortgage obligations (CMO) include securities issued by the Government National Mortgage Association (GNMA), a U.S. government agency, and the Federal National Mortgage Association (FNMA), the Federal Home Loan Mortgage Corporation (FHLMC), and the Federal Home Loan Bank (FHLB), which are U.S. government-sponsored enterprises.

Debt securities with carrying values aggregating approximately $204.8 million and $153.9 million at September 30, 2021 and December 31, 2020, respectively, were pledged to secure public funds, securities sold under agreements to repurchase, and for other purposes as required or permitted by law.

The amortized cost and fair value of debt securities classified as available-for-sale at September 30, 2021, by contractual maturity are shown below. Expected maturities may differ from contractual maturities because borrowers have the right to call or prepay obligations with or without prepayment penalties.


	Amortized		Fair
(in thousands)	Cost		Value
Due in one year or less	$	4,776	$	4,798
Due after one year through five years		12,576		12,734
Due after five years through ten years		34,073		34,890
Due after ten years		101,931		101,093
Total		153,356		153,515
Mortgage-backed securities		125,126		125,013
Total available-for-sale securities	$	278,482	$	278,528

Other securities

Other investment securities include equity securities with readily determinable fair values and other investment securities that do not have readily determinable fair values. Investments in FHLB stock, and Midwest Independent Bank (MIB) bankers bank stock, that do not have readily determinable fair values, are required for membership in those organizations.


	September 30,		December 31,
(in thousands)	2021		2020
Other securities:
FHLB stock	$	5,812	$	6,170
MIB stock		151		151
Equity securities with readily determinable fair values		52		32
Total other investment securities	$	6,015	$	6,353

Gross unrealized losses on debt securities and the fair value of the related securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position, at September 30, 2021 and December 31, 2020 were as follows:


	Less than 12 months				12 months or more
									Total		Total
	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(in thousands)	Value		Losses *		Value		Losses		Value		Losses
At September 30, 2021
U.S. Treasury	$	508	$	—	$	—	$	—	$	508	$	—
U.S. government-sponsored enterprises		4,892		(108)		—		—		4,892		(108)
Obligations of states and political subdivisions		62,391		(1,382)		—		—		62,391		(1,382)
Mortgage-backed securities		70,027		(1,324)		1,667		(10)		71,694		(1,334)
Bank issued trust preferred securities		—		—		1,281		(205)		1,281		(205)
Total	$	137,818	$	(2,814)	$	2,948	$	(215)	$	140,766	$	(3,029)

(in thousands)
At December 31, 2020
U.S. Treasury	$	1,015	$	—	$	—	$	—	$	1,015	$	—
Mortgage-backed securities		7,494		(54)		—		—		7,494		(54)
Other debt securities		2,987		(14)		—		—		2,987		(14)
Bank issued trust preferred securities		—		—		1,229		(257)		1,229		(257)
Total	$	11,496	$	(68)	$	1,229	$	(257)	$	12,725	$	(325)

* Amounts less than $1,000 are not reported

The total available-for-sale portfolio consisted of approximately 417 securities at September 30, 2021. The portfolio included 157 securities having an aggregate fair value of $140.8 million that were in a loss position at September 30, 2021. Securities identified as temporarily impaired which had been in a loss position for 12 months or longer totaled $2.9 million at fair value at September 30, 2021. The $3.0 million aggregate unrealized loss included in accumulated other comprehensive loss at September 30, 2021 was caused by interest rate fluctuations.

The total available-for-sale portfolio consisted of approximately 308 securities at December 31, 2020. The portfolio included 10 securities having an aggregate fair value of $12.7 million that were in a loss position at December 31, 2020. Securities identified as temporarily impaired which had been in a loss position for 12 months or longer totaled $1.2 million at fair value at December 31, 2020. The $325,000 aggregate unrealized loss included in accumulated other comprehensive loss at December 31, 2020 was caused by interest rate fluctuations.

Because the decline in fair value is attributable to changes in interest rates and not credit quality, these investments were not considered other-than-temporarily impaired at September 30, 2021 and December 31, 2020, respectively. In the absence of changes in credit quality of these investments, the fair value is expected to recover on all debt securities as they approach their maturity date or re-pricing date, or if market yields for such investments decline. In addition, the Company does not have the intent to sell these investments over the period of recovery, and it is not more likely than not that the Company will be required to sell such investment securities.

The following table presents the gross realized gains and losses from sales and calls of available-for-sale securities, as well as gains and losses on equity securities from fair value adjustments which have been recognized in earnings:


	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands)	2021		2020		2021		2020
Investment securities gains, net
Available-for-sale securities:
Gross realized gains	$	119	$	21	$	121	$	27
Gross realized losses		—		(8)		—		(8)
Other-than-temporary impairment recognized		—		—		—		—
Other investment securities:
Fair value adjustments, net		7		(1)		19		(1)
Investment securities gains, net	$	126	$	12	$	140	$	18