Prospectus Filed Pursuant to Rule 424(b)(3) (424b3)

Filed pursuant to Rule 424(b)(3)

SEC File No. 333-258223

PROSPECTUS SUPPLEMENT NO. 2

(to Prospectus dated October 5, 2021)

LOGO

ironSource Ltd.

102,869,375 CLASS A ORDINARY SHARES

This prospectus supplement updates, amends and supplements the prospectus contained in our Post-Effective Amendment No. 1 to our Registration Statement on Form F-1, effective as of October 4, 2021 (as supplemented or amended from time to time, the “Prospectus”) (Registration No. 333-258223). Capitalized terms used in this prospectus supplement and not otherwise defined herein have the meanings specified in the Prospectus.

This prospectus supplement is being filed to update, amend and supplement the information included in the Prospectus with information on ironSource’s third quarter 2021 financial results, which is set forth below.

This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read in conjunction with the Prospectus, which is to be delivered with this prospectus supplement, and is qualified by reference thereto, except to the extent that the information in this prospectus supplement updates or supersedes the information contained in the Prospectus. Please keep this prospectus supplement with your Prospectus for future reference.

Our Class A ordinary shares are listed on the New York Stock Exchange under the symbol “IS.” On November 9, 2021, the closing price for our Class A ordinary shares on the New York Stock Exchange was $12.04 per share.

Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 28 of the Prospectus and other risk factors contained in the documents incorporated by reference therein for a discussion of information that should be considered in connection with an investment in our securities.

Neither the Securities and Exchange Commission, the Israeli Securities Authority nor any state securities commission has approved or disapproved of these securities or determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is November 10, 2021.

IRONSOURCE LTD.

CONDENSED CONSOLIDATED BALANCE SHEETS

(U.S. dollars in thousands, except for number of shares and par value)

(Unaudited)


	September 30,		December 31,
	2021		2020
Assets
Current assets:
Cash and cash equivalents	$	787,961	$	200,672
Short-term deposits		—		17,627
Accounts receivable, net of allowances of $761 and $724 as of September 30, 2021 and December 31, 2020, respectively		188,994		151,503
Other current assets		32,920		15,711

Total current assets		1,009,875		385,513
Long-term restricted cash		2,912		2,415
Deferred tax assets		3,344		161
Operating lease right-of-use asset		32,306		36,780
Property, equipment and software, net		24,791		23,077
Investment in equity securities		20,000		—
Goodwill		205,842		79,156
Intangible assets, net		29,677		8,084
Other non-current assets		6,774		650

Total assets	$	1,335,521	$	535,836

IRONSOURCE LTD.

CONDENSED CONSOLIDATED BALANCE SHEETS

(U.S. dollars in thousands, except for number of shares and par value)

(Unaudited)


	September 30			December 31,
	2021			2020
Liabilities and shareholders’ equity
Current liabilities:
Accounts payable	$	213,205		$	155,476
Current maturities of long-term loan		—			9,725
Operating lease liabilities		6,002			7,429
Other current liabilities		38,991			34,034

Total current liabilities		258,198			206,664
Long-term loan, net of current maturities		—			74,684
Deferred tax liabilities		1,163			2,521
Long-term operating lease liabilities		28,655			32,241
Other non-current liabilities		1,555			280

Total liabilities		289,571			316,390

Commitments and contingencies
Shareholders’ equity:
Class A ordinary share, no par value; 10,000,000,000 shares authorized at September 30, 2021 and December 31, 2020; 631,082,097 and 320,133,022 issued and outstanding at September 30, 2021 and December 31, 2020, respectively ⁽¹⁾		—			—
Class B ordinary share, no par value; 1,500,000,000 shares authorized at September 30, 2021 and December 31, 2020; 384,150,417 and 320,133,022 issued and outstanding at September 30, 2021 and December 31, 2020, respectively ⁽¹⁾		—			—
2019 ordinary shares, NIS 0.01 par value, 25,006,298 authorized, issued and outstanding at December 31, 2020		—			72
Treasury shares, at cost, 6,745,955 Class A ordinary shares held at September 30, 2021		(67,460	)		—
Additional paid-in capital ⁽¹⁾		1,007,271			152,251
Retained earnings		106,139			67,123

Total shareholders’ equity		1,045,950			219,446

Total liabilities and shareholders’ equity	$	1,335,521		$	535,836

⁽¹⁾	Per share amounts have been adjusted, on a retroactive basis, for all periods presented, to reflect both the distribution of Class B ordinary shares and the Stock Split, together representing a ratio of 9.98 of each share.

IRONSOURCE LTD.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(U.S. dollars in thousands, except share and per share amounts)

(Unaudited)


	Three Months Ended September 30,				Nine Months Ended September 30,
	2021		2020		2021		2020
Revenue	$	140,446	$	88,001	$	395,195	$	223,165
Cost of revenue		21,756		15,416		64,661		40,519

Gross profit		118,690		72,585		330,534		182,646

Operating expenses:
Research and development		24,073		12,851		67,644		34,451
Sales and marketing		51,001		29,805		151,903		77,216
General and administrative		20,212		6,353		56,445		19,836

Total operating expenses		95,286		49,009		275,992		131,503

Income from operations		23,404		23,576		54,542		51,143
Financial expenses, net		55		434		2,061		2,610

Income from continuing operations before income taxes		23,349		23,142		52,481		48,533
Income taxes		4,581		3,256		13,465		7,044

Income from continuing operations, net of income taxes		18,768		19,886		39,016		41,489
Income from discontinued operations, net of income taxes		—		6,991		—		31,779

Net income	$	18,768	$	26,877	$	39,016	$	73,268

Basic net income per ordinary share: ⁽¹⁾
Continuing operations		0.02		0.02		0.04		0.05
Discontinued operations		—		0.01		—		0.03

Basic net income per ordinary share	$	0.02	$	0.03	$	0.04	$	0.08

Weighted-average ordinary shares outstanding – basic		1,014,267,611		636,578,068		772,837,797		635,526,458

Diluted net income per ordinary share: ⁽¹⁾
Continuing operations		0.02		0.02		0.04		0.04
Discontinued operations		—		0.01		—		0.04

Diluted net income per ordinary share	$	0.02	$	0.03	$	0.04	$	0.08

Weighted-average ordinary shares outstanding – diluted		1,095,048,098		688,072,259		851,235,852		679,226,389

⁽¹⁾	Per share amounts have been adjusted, on a retroactive basis, for all periods presented, to reflect both the distribution of Class B ordinary shares and the Stock Split, together representing a ratio of 9.98 of each share.

IRONSOURCE LTD.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(U.S. dollars in thousands)

(Unaudited)


	Three months Ended September 30,						Nine months Ended September 30,
	2021			2020			2021			2020
	(Unaudited)						(Unaudited)
Cash flows from operating Activities
Net income from continuing operations	$	18,768		$	19,886		$	39,016		$	41,489
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization		6,211			4,091			17,428			12,230
Share-based compensation expenses		20,327			2,250			57,801			7,591
Non-cash lease expense		(1,381	)		330			(539	)		320
Effect of exchange rate changes on cash and cash equivalents and restricted cash		(676	)		(436	)		(815	)		12
Gain on disposal of fixed assets		(17	)		—			(17	)		—
Interest accrued and other financial expenses		—			53			628			161
Deferred income taxes, net		194			(603	)		(534	)		(1,298	)
Changes in operating assets and liabilities:
Accounts receivable		(2,150	)		(9,118	)		(41,016	)		(14,381	)
Other current assets		1,184			(1,125	)		(17,460	)		655
Other non-current assets		(2,017	)		(625	)		(10,054	)		(2,167	)
Accounts payable		43,401			14,321			63,769			17,256
Other current liabilities		7,220			4,844			5,667			4,428
Other long-term liabilities		(206	)		(11	)		1,275			31

Net cash provided by continuing operating activities		90,858			33,857			115,149			66,327
Net cash provided by (used in) discontinued operating activities		—			15,609			(5,168	)		46,583

Net cash provided by operating activities		90,858			49,466			109,981			112,910

Cash flows from investing activities
Purchase of property, plant and equipment		(268	)		(124	)		(1,028	)		(955	)
Capitalized software development costs		(2,557	)		(3,291	)		(8,159	)		(9,056	)
Purchase of intangible assets		—			—			(1,950	)		—
Consideration received from sale of fixed assets		21			—			21			—
Acquisitions, net of cash acquired		—			—			(90,184	)		—
Purchase of equity investment		—			—			(20,000	)		—
Investments in short-term deposits		—			(37,590	)		—			(42,590	)
Maturities of short-term deposits		—			5,000			17,590			13,100

Net cash used in continuing investing activities		(2,804	)		(36,005	)		(103,710	)		(39,501	)
Net cash used in discontinued investing activities		—			(1,214	)		—			(4,154	)

Net cash used in investing activities		(2,804	)		(37,219	)		(103,710	)		(43,655	)

Cash flows from financing activities
Repayment of long-term loan		—			(2,500	)		(85,000	)		(5,000	)
Proceeds from Recapitalization transaction, net		(9,080	)		—			663,813			—
Exercise of options		1,545			243			1,887			904

Net cash provided (used in) continuing financing activities		(7,535	)		(2,257	)		580,700			(4,096	)
Net cash provided (used in) discontinued financing activities		—			—			—			—

Net cash provided (used in) financing activities		(7,535	)		(2,257	)		580,700			(4,096	)

Effect of exchange rate changes on cash and cash equivalents and restricted cash		676			436			815			(12	)
Net change in cash and cash equivalents and restricted cash		80,519			9,990			586,971			65,159
Cash and cash equivalents and restricted cash at beginning of the period		709,678			145,940			203,087			91,219

Cash and cash equivalents and restricted cash at end of the period	$	790,873		$	156,366		$	790,873		$	156,366