Investment securities held by the Company consist of the following investments in corporate bonds and equity securities:


(in thousands of $)	June 30, 2021	December 31, 2020
Corporate Bonds	8,293	9,431
Equity Securities	14,512	19,374

Total Investment in Debt and Equity Securities	22,805	28,805

The corporate bonds are classified as available-for-sale securities and are recorded at fair value, with unrealized gains and losses recorded as a separate component of "Other comprehensive income".


	Six months ended June 30, 2021			Year ended December 31, 2020
(in thousands of $)	Amortized Cost	Unrealized gains/(losses)	Fair value	Amortized Cost	Unrealized gains/(losses)	Fair value
Corporate bonds:
NorAm Drilling Bond	4,132	488	4,620	4,132	511	4,643


NT Rig Holdco 12%	3,567	106	3,673	3,567	404	3,971
NT Rig Holdco 7.5%	—	—	—	817	—	817
Total corporate bonds	7,699	594	8,293	8,516	915	9,431

During the year ended December 31, 2020, the existing Oro Negro 12% and 7.5% bonds completed a conversion that resulted in the recognition of NT Rig Holdco Liquidity 12% and NT Rig Holdco 7.5% bonds and the redemption of the Oro Negro 12% bonds in full and a substantial proportion of the Oro Negro 7.5% bonds. The Company recorded no gain or loss on the redemption of the bonds. The Company also acquired an additional $1.3 million of the NT Rig Holdco 12% bonds in the year ended December 31, 2020.

Also, during the year ended December 31, 2020, it was determined that the Oro Negro 7.5% bonds and the NT Rig Holdco 7.5% bonds were other-than-temporarily impaired and an aggregate impairment loss of $4.9 million was recorded in the Consolidated Statement of Operations. During the six months ended June 30, 2021, an impairment loss of $0.8 million was recorded against the NT Rig Holdco 7.5% bonds.


(in thousands of $)	June 30, 2021	December 31, 2020
Frontline	13,032	9,007
NorAm Drilling	1,480	1,484
ADS Maritime Holding	—	8,883
Total Equity Securities	14,512	19,374

Equity Securities pledged to creditors	13,032	9,007

In March 2021, the Company received a capital dividend of approximately $8.8 million from ADS Maritime Holding following the sale of its remaining two vessels. Also in March 2021, the Company sold its remaining shares in ADS Maritime Holding for a consideration of $0.8 million and recognized a gain of $0.7 million in the Statement of Operations in relation to the disposal.

As at June 30, 2021, the Company held approximately 1.4 million shares of Frontline Ltd ("Frontline"), a related party (December 31, 2020: 1.4 million shares). Refer to Note 17: Related Party Transactions.

In December 2019, the Company entered into a forward contract to repurchase 3.4 million shares of Frontline in June 2020 for $36.8 million. During the year ended December 31, 2020, the Company repurchased and simultaneously sold approximately 2.0 million shares in Frontline for total proceeds of $21.1 million and recorded gains of $2.3 million in the statement of operations in respect of the sales.

As at December 31, 2020, the Company had a forward contract, which expired in January 2021, to repurchase 1.4 million shares of Frontline at a repurchase price of $16.2 million. The transaction has been accounted for as a secured borrowing, with the shares transferred to 'Marketable securities pledged to creditors' and a liability of $15.6 million recorded within debt at June 30, 2021 (December 31, 2020: $15.6 million) (See also Note 12: Short-Term and Long-Term Debt).