The following table summarizes activity in the unrealized gain or loss on available for sale securities included in other comprehensive income (loss) for the three months ended March 31, 2022 and 2021.


	For the three months ended March 31,
	2022		2021
Balance at beginning of period	$	(1,718,000)	$	5,009,000
Unrealized losses arising during the period	(23,217,000)		(5,945,000)
Reclassification of net realized gains during the period	(2,000)		(119,000)
Related deferred taxes	4,876,000		1,274,000
Net change	(18,343,000)		(4,790,000)
Balance at end of period	$	(20,061,000)	$	219,000

The reclassification of realized gains is included in the net securities gains line of the consolidated statements of income and comprehensive income and the tax effect is included in the income tax expense line of the same statement.

The following table summarizes activity in the unrealized loss on securities transferred from available for sale to held to maturity included in other comprehensive income (loss) for the three months ended March 31, 2022 and 2021.


	For the three months ended March 31,
	2022		2021
Balance at beginning of period	$	(87,000)	$	(133,000)

Amortization of net unrealized gains	12,000		11,000
Related deferred taxes	(3,000)		(2,000)
Net change	9,000		9,000
Balance at end of period	$	(78,000)	$	(124,000)

The following table presents the effect of the Company's derivative financial instruments included in other comprehensive income (loss) for the three months ended March 31, 2022 and 2021.


	For the three months ended March 31,
	2022		2021
Balance at beginning of period	$	—	$	(4,932,000)
Unrealized gains on cash flow hedging derivatives arising during the period	—		4,390,000

Related deferred taxes	—		(921,000)
Net change	—		3,469,000
Balance at end of period	$	—	$	(1,463,000)

There was no activity in the unrealized gain or loss on postretirement benefits included in other comprehensive income (loss) for the three months ended March 31, 2022 and 2021.