8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

____________________________________________________________________________

FORM 8-K

____________________________________________________________________________

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported)

October 29, 2019

____________________________________________________________________________

A10 NETWORKS, INC.

(Exact name of registrant as specified in its charter)

____________________________________________________________________________

Delaware	001-36343	20-1446869
(State or Other Jurisdiction of Incorporation or Organization)	(Commission File Number)	(I.R.S. Employer Identification Number)

3 West Plumeria Drive

San Jose, CA 95134

(Address of principal executive offices, including zip code)

(408) 325-8668

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

[ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, $0.00001 par value	ATEN	New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

	Emerging growth company	x
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.		x

Item 2.02. Results of Operations and Financial Condition.

On October 29, 2019, A10 Networks, Inc. (the “Company”) issued a press release regarding financial results for the quarter ended September 30, 2019. The Company also posted on its website (www.a10networks.com) slides with accompanying prepared remarks regarding such financial results. Copies of the press release and slides with accompanying prepared remarks by the Company are attached as Exhibits 99.1 and 99.2, respectively, and the information in Exhibits 99.1 and 99.2 are incorporated herein by reference.

The information in Item 2.02 and Item 9.01 in this Current Report on Form 8-K and the exhibits attached hereto shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section, nor shall it be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended.

Item 2.05. Costs Associated with Exit or Disposal Activities.

On October 28, 2019, the Company began implementing a workforce reduction of approximately 5% of the Company’s workforce, which the Company expects to complete by the end of the second fiscal quarter of 2020. The Company estimates that it will incur restructuring charges of approximately $2 million, all of which will be expensed in the fourth fiscal quarter of 2019, primarily related to cash severance payments.

Item 9.01. Financial Statements and Exhibits

(d) Exhibits

Exhibit	Description
99.1	Press release, dated October 29, 2019, regarding financial results of A10 Networks, Inc. for the third quarter ended September 30, 2019.
99.2	Slides with accompanying prepared remarks of A10 Networks, Inc., dated October 29, 2019, regarding financial results of the third quarter ended September 30, 2019.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: October 29, 2019

A10 NETWORKS, INC.

By: /s/ Tom Constantino

Tom Constantino

Executive Vice President and Chief Financial Officer

(Principal Accounting and Financial Officer)

EX-99.1

EXHIBIT 99.1

A10 Networks Reports Third Quarter 2019 Financial Results and Fourth Quarter Outlook

Third Quarter Revenue Grew 7% Sequentially, Above Midpoint of Prior Guidance

Expects Fourth Quarter Sequential Revenue Growth of 8% at Midpoint of Range

SAN JOSE, Calif., October 29, 2019 -- A10 Networks (NYSE: ATEN), a leading provider of intelligent and automated cybersecurity solutions, today announced financial results for its third quarter ended September 30, 2019.

Third Quarter 2019 Financial Summary

• Revenue of $52.8 million, up 7 percent compared with $49.2 million in second quarter 2019

• GAAP gross margin of 77.4 percent, non-GAAP gross margin of 78.1 percent

• GAAP operating expenses of $40.7 million, non-GAAP operating expenses of $39.4 million

• GAAP net income of $0.2 million, or $0.00 per basic and diluted share, non-GAAP net income of $1.8 million, or $0.02 per basic and diluted share

• Adjusted EBITDA of $4.0 million, compared with $1.3 million in second quarter 2019

A reconciliation between GAAP and non-GAAP information is contained in the financial statements below.

“We delivered results in the third quarter that were in-line to above our most recent guidance. Our revenue increased 7% sequentially, and we were pleased with improving demand from our service provider vertical, which grew 36% versus the prior quarter. We also saw continued strength in 5G security in South Korea, Japan, and the Middle East.” said Lee Chen, president and chief executive officer of A10 Networks. “We are optimistic as we look to the fourth quarter and beyond, due to improving demand signals from several key North America accounts, expanded 5G security infrastructure deployments on the part of service providers across the globe, an ongoing positive mix shift toward more recurring maintenance and subscription revenue, and the fact that the company is laser-focused on making progress to accelerate operating income.”

Fourth Quarter 2019 Business Outlook (+)

For the fourth quarter of 2019, the company currently expects:

• Revenue in the range of $55 million to $59 million, representing 8 percent sequential growth at the midpoint

• Non-GAAP gross margin in the range of 76 percent to 78 percent

• Non-GAAP operating expenses in the range of $39 million to $40 million, excluding anticipated charges for severance and restructuring of approximately $2 million

• Adjusted EBITDA in the range of $5.4 million to $8.2 million

• Non-GAAP earnings per share in the range of $0.04 to $0.08 using approximately 80 million basic and diluted shares

(+) Please refer to the note below on forward-looking statements and the risks involved with such statements as well as the note on non-GAAP financial measures.

Company Update

Review of strategic alternatives by Strategy Committee of the Board

The Strategy Committee continues to evaluate opportunities to maximize shareholder value.

Search Committee of the Board directed at supporting CEO succession

The Search Committee continues to evaluate CEO candidates. The Company continues to have the full commitment of current president and chief executive officer Lee Chen until the CEO role is transitioned to his successor.

Prepared Materials and Conference Call Information

A10 Networks has made available a presentation with management’s prepared remarks on its third quarter 2019 financial results. These materials are accessible from the “Investor Relations” section of the A10 Networks website at investors.a10networks.com.

A10 Networks will host a conference call today at 4:30 p.m. Eastern time / 1:30 p.m. Pacific time for analysts and investors to discuss its third quarter 2019 financial results and outlook for its fourth quarter 2019. Open to the public, investors may access the call by dialing +1-844-792-3728 or +1-412-317-5105. A live audio webcast of the conference call will be accessible from the “Investor Relations” section of the A10 Networks website at investors.a10networks.com. The webcast will be archived for a period of one year. A telephonic replay of the conference call will be available two hours after the call, will run for five business days, and may be accessed by dialing +1-877-344-7529 or +1-412-317-0088 and entering the passcode 101358845. The press release and supplemental financials will be accessible from the “Investor Relations” section of the A10 Networks website prior to the commencement of the conference call.

Forward-Looking Statements

This press release contains “forward-looking statements,” including statements regarding our pipeline; projections for our future operating results, optimism for the fourth quarter and beyond; improving demand signals in North America; accelerating operating income; an ongoing positive mix shift toward more recurring maintenance and subscription revenue; our plans to evaluate strategic alternatives; the timing of completing a search for a CEO successor and the commitment form Mr. Chen that he will remain fully committed until a successor is appointed; and our planned implementation of a reduction in force. Forward-looking statements are subject to known and unknown risks and uncertainties and are based on assumptions that may prove to be incorrect, which could cause actual results to differ materially from those expected or implied by the forward-looking statements. Factors that may cause actual results to differ include execution risks related to closing key deals and improving our execution, the continued market adoption of our products, our ability to successfully anticipate market needs and opportunities, our timely development of new products and features, our ability to achieve or maintain profitability, any loss or delay of expected purchases by our largest end-customers, our ability to maintain or improve our competitive position, competitive and execution risks related to cloud-based computing trends, our ability to attract and retain new end-customers and our largest end-consumers, our ability to maintain and enhance our brand and reputation, changes demanded by our customers in the deployment and payment model for our products, continued growth in markets relating to network security, the success of any future acquisitions or investments in complementary companies, products, services or technologies, the ability of our sales team to execute well, our ability to shorten our close cycles, the ability of our channel partners to sell our products, variations in product mix or geographic locations of our sales, risks associated with our presence in international markets, weaknesses or

deficiencies in our internal control over financial reporting, and our ability to timely file periodic reports required to be filed under the Securities Exchange Act of 1934.

Non-GAAP Financial Measures

In addition to disclosing financial measures prepared in accordance with U.S. generally accepted accounting principles (GAAP), this press release and the accompanying table contain certain non-GAAP financial measures, including non-GAAP net income (loss), non-GAAP gross profit, non-GAAP operating income (loss) and EBITDA. Non-GAAP financial measures do not have any standardized meaning and are therefore unlikely to be comparable to similarly titled measures presented by other companies.

A10 Networks considers these non-GAAP financial measures to be important because they provide useful measures of the operating performance of the company, exclusive of unusual events or factors that do not directly affect what we consider to be our core operating performance, and are used by the company's management for that purpose. We define non-GAAP net income (loss) as our GAAP net income (loss) excluding: (i) stock-based compensation and related payroll tax, (ii) amortization expense related to acquisition and (iii) non-recurring expenses associated with the litigation settlement expense and internal investigation. We define non-GAAP gross profit as our GAAP gross profit excluding stock-based compensation and related payroll tax. We define non-GAAP operating income (loss) as our GAAP income (loss) from operations excluding (i) stock-based compensation, and related tax, (ii) amortization expense related to acquisition and (iii) non-recurring expenses associated with the litigation settlement expense and internal investigation. We define EBITDA as our GAAP net income (loss) excluding (i) interest expense, (ii) interest income and other (income) expense, net, (iii) depreciation and amortization expense and (iv) provision for income taxes.

We have included our non-GAAP net income (loss), non-GAAP gross profit, non-GAAP operating income (loss) and EBITDA in this press release. Non-GAAP financial measures are presented for supplemental informational purposes only for understanding the company's operating results. The non-GAAP financial measures should not be considered a substitute for financial information presented in accordance with GAAP, and may be different from non-GAAP financial measures presented by other companies. Please see the reconciliation of non-GAAP financial measures to the most directly comparable GAAP measure attached to this release. A reconciliation of non-GAAP guidance measures to corresponding GAAP measures on a forward-looking basis is not available due to high variability and low visibility with respect to the charges which are excluded from these non-GAAP measures.

About A10 Networks

A10 Networks (NYSE: ATEN) provides Reliable Security Always™, with a range of high-performance application networking solutions that help organizations ensure that their data center applications and networks remain highly available, accelerated and secure. Founded in 2004, A10 Networks is based in San Jose, Calif., and serves customers globally with offices worldwide. For more information, visit: www.a10networks.com and @A10Networks.

The A10 logo and A10 Networks are trademarks or registered trademarks of A10 Networks, Inc. in the United States and other countries. All other trademarks are the property of their respective owners.

Investor Contact:

Chris Mammone

The Blueshirt Group

investors@a10networks.com

Source: A10 Networks, Inc.

A10 NETWORKS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(unaudited, in thousands, except per share amounts)

	Three Months Ended   September 30,						Nine Months Ended   September 30,
	2019			2018			2019			2018
Revenue:
Products	$	30,052		$	38,265		$	85,067		$	105,638
Services	22,781			22,237			67,245			64,760
Total revenue	52,833			60,502			152,312			170,398
Cost of revenue:
Products	7,108			8,790			21,515			24,979
Services	4,812			4,224			13,926			13,106
Total cost of revenue	11,920			13,014			35,441			38,085
Gross profit	40,913			47,488			116,871			132,313
Operating expenses:
Sales and marketing	22,056			24,539			70,165			77,231
Research and development	15,784			15,505			46,567			49,874
General and administrative	2,854			9,012			17,311			30,464
Total operating expenses	40,694			49,056			134,043			157,569
Income (loss) from operations	219			(1,568		)	(17,172		)	(25,256		)
Non-operating income (expense):
Interest expense	(30		)	(34		)	(222		)	(99		)
Interest and other income (expense), net	254			(131		)	397			6
Total non-operating income (expense), net	224			(165		)	175			(93		)
Income (loss) before provision for income taxes	443			(1,733		)	(16,997		)	(25,349		)
Provision for income taxes	270			74			873			660
Net income (loss)	$	173		$	(1,807	)	$	(17,870	)	$	(26,009	)
Net income (loss) per share:
Basic	$	—		$	(0.02	)	$	(0.24	)	$	(0.36	)
Diluted	$	—		$	(0.02	)	$	(0.24	)	$	(0.36	)
Weighted-average shares used in computing net income (loss) per share:
Basic	76,618			72,707			75,611			72,550
Diluted	79,093			72,707			75,611			72,550

A10 NETWORKS, INC.

RECONCILIATION OF GAAP NET INCOME (LOSS) TO NON-GAAP NET INCOME (LOSS)

(unaudited, in thousands, except per share amounts)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
GAAP net income (loss)	$	173		$	(1,807	)	$	(17,870	)	$	(26,009	)
Stock-based compensation and related payroll tax	3,513			2,333			12,458			13,055
Amortization expense related to acquisition	253			253			759			758
Litigation and investigation expense	(2,157		)	1,531			(1,108		)	9,031
Non-GAAP net income (loss)	$	1,782		$	2,310		$	(5,761	)	$	(3,165	)
Non-GAAP net income (loss) per share:
Basic and diluted	$	0.02		$	0.03		$	(0.08	)	$	(0.04	)
Weighted average shares used in computing non-GAAP net income (loss) per share:
Basic	76,618			72,707			75,611			72,550
Diluted	79,093			74,940			75,611			72,550

A10 NETWORKS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(unaudited, in thousands, except per share data)

	September 30, 2019			December 31, 2018
ASSETS
Current assets:
Cash and cash equivalents	$	36,067		$	40,621
Marketable securities	86,525			87,754
Accounts receivable, net of allowances of $52 and $319, respectively	45,397			53,972
Inventory	21,081			17,930
Prepaid expenses and other current assets	14,509			14,662
Total current assets	203,579			214,939
Property and equipment, net	8,846			7,262
Goodwill	1,307			1,307
Intangible assets	2,666			3,748
Other non-current assets	12,549			8,620
Total assets	$	228,947		$	235,876
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	5,488		$	8,202
Accrued liabilities	20,735			25,291
Deferred revenue	59,603			63,874
Total current liabilities	85,826			97,367
Deferred revenue, non-current	38,470			34,092
Other non-current liabilities	2,483			534
Total liabilities	126,779			131,993
Stockholders' equity:
Common stock, $0.00001 par value: 500,000 shares authorized; 76,744 and 74,301 shares issued and outstanding, respectively	1			1
Additional paid-in-capital	391,998			376,272
Accumulated other comprehensive income (loss)	285			(144		)
Accumulated deficit	(290,116		)	(272,246		)
Total stockholders' equity	102,168			103,883
Total liabilities and stockholders' equity	$	228,947		$	235,876

A10 NETWORKS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(unaudited, in thousands)

	Nine Months Ended September 30,
	2019			2018
Cash flows from operating activities:
Net loss	$	(17,870	)	$	(26,009	)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	7,433			6,020
Stock-based compensation	12,221			13,055
Other non-cash items	(422		)	152
Changes in operating assets and liabilities:
Accounts receivable	8,735			(3,144		)
Inventory	(4,222		)	1,550
Prepaid expenses and other assets	468			(868		)
Accounts payable	(3,172		)	806
Accrued and other liabilities	(9,183		)	(1,482		)
Deferred revenue	107			4,219
Other	—			183
Net cash used in operating activities	(5,905		)	(5,518		)
Cash flows from investing activities:
Proceeds from sales of marketable securities	22,189			23,194
Proceeds from maturities of marketable securities	33,449			41,732
Purchases of marketable securities	(53,852		)	(67,754		)
Purchase of investment	—			(1,000		)
Purchases of property and equipment	(3,939		)	(2,252		)
Net cash used in investing activities	(2,153		)	(6,080		)
Cash flows from financing activities:
Proceeds from issuance of common stock under employee equity incentive plans	3,505			1,269
Other	(1		)	(76		)
Net cash provided by financing activities	3,504			1,193
Net decrease in cash and cash equivalents	(4,554		)	(10,405		)
Cash and cash equivalents - beginning of period	$	40,621		$	46,567
Cash and cash equivalents - end of period	$	36,067		$	36,162

A10 NETWORKS, INC.

RECONCILIATION OF GAAP GROSS PROFIT TO NON-GAAP GROSS PROFIT

(unaudited, in thousands, except percentages)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
GAAP gross profit	$	40,913		$	47,488		$	116,871		$	132,313
GAAP gross margin	77.4		%	78.5		%	76.7		%	77.6		%
Non-GAAP adjustments:
Stock-based compensation and related payroll tax	334			187			1,126			1,277
Non-GAAP gross profit	$	41,247		$	47,675		$	117,997		$	133,590
Non-GAAP gross margin	78.1		%	78.8		%	77.5		%	78.4		%

RECONCILIATION OF GAAP INCOME (LOSS) FROM OPERATIONS TO

NON-GAAP OPERATING INCOME (LOSS)

(unaudited, in thousands, except percentages)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
GAAP income (loss) from operations	$	219		$	(1,568	)	$	(17,172	)	$	(25,256	)
GAAP operating margin	0.4		%	(2.6		)%	(11.3		)%	(14.8		)%
Non-GAAP adjustments:
Stock-based compensation and related payroll tax	3,513			2,333			12,458			13,055
Amortization expense related to acquisition	253			253			759			758
Litigation and investigation expense	(2,157		)	1,531			(1,108		)	9,031
Non-GAAP operating income (loss)	$	1,828		$	2,549		$	(5,063	)	$	(2,412	)
Non-GAAP operating margin	3.5		%	4.2		%	(3.3		)%	(1.4		)%

RECONCILIATION OF GAAP NET INCOME (LOSS) TO EBITDA AND ADJUSTED EBITDA (NON-GAAP)

(unaudited, in thousands)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2019			2018			2019			2018
GAAP net income (loss)	$	173		$	(1,807	)	$	(17,870	)	$	(26,009	)
Exclude: Interest expense	30			34			222			99
Exclude: Interest income and other (income) expense, net	(254		)	131			(397		)	(6		)
Exclude: Depreciation and amortization expense	2,451			1,917			7,433			6,020
Exclude: Provision for income tax expense	270			74			873			660
EBITDA	2,640			184			(9,564		)	(19,329		)
Exclude: Stock-based compensation and related payroll tax	3,513			2,333			12,458			13,055
Exclude: Litigation settlement and investigation expense	(2,157		)	1,531			(1,108		)	9,031
Adjusted EBITDA	$	4,026		$	4,213		$	1,611		$	2,850

EX-99.2

Reliable Security Always Q3 2019 FINANCIAL RESULTS & COMMENTARY October 29, 2019 Reliable Security Always™

CAUTIONARY STATEMENTS & DISCLOSURES This presentation and the accompanying oral presentation contain “forward-looking” statements that are based on our management’s beliefs and assumptions, including statements regarding our projections for our future operating results, including our belief that we will see a sequential increase in revenue during the fourth quarter, increased recurring revenue in 2020, our focus on business optimization and overall profitability, including through a reduction in force, our pursuit of potential alternatives to create shareholder value, our CEO succession plan, the capabilities of our sales team, the refining of our marketing engine, our expectations regarding future opportunities and our ability to execute on those opportunities, our commitment to innovation and bringing new solutions to market, our expectations for future market growth and the general growth of our business, the development and performance of our products, our current and future strategies, our beliefs relating to our competitive advantages, anticipated customer benefits from use of our products, our expectations and priorities with respect to 5G, responses to new security threats, our partnerships with key technology providers and sales partnerships, and our ability to penetrate certain markets. Forward-looking statements are subject to known and unknown risks, uncertainties, assumptions and other factors that could cause our actual results to differ materially from those anticipated or implied by our forward-looking statements. These factors include, but are not limited to, successfully executing our strategies, market adoption of our products, successfully anticipating market needs and opportunities, timely development of new products and features, achieving or maintaining profitability, loss or delay of expected purchases, attracting and retaining new end-customers, maintaining and enhancing our brand and reputation, growth in markets relating to network security, the success of any future acquisitions or investments, the success of our partnerships with technology providers, our ability to shorten our close cycle, the ability of our channel partners to sell our products, our presence in international markets, and other factors described in our quarterly reports on Form 10-Q, annual reports on Form 10-K and other filings made with the Securities and Exchange Commission, to which your attention is directed. We assume no responsibility for the accuracy and completeness of the forward-looking statements and disclaim any obligation to update information contained in these forward-looking statements. This presentation and the accompanying oral presentation also include certain non-GAAP financial measures. Non-GAAP financial measures have limitations as analytical tools and you should not consider them in isolation or as a substitute for an analysis of our results under U.S. GAAP. Definitions of our non-GAAP financial measures and a reconciliation between GAAP and non-GAAP financial measures can be found in the appendix to this document and in the accompanying financial results press release. A reconciliation of non-GAAP guidance measures to corresponding GAAP measures on a forward-looking basis is not available due to high variability and low visibility with respect to the charges which are excluded from these non-GAAP measures. 2

AGENDA • Introduction ◦ Chris Mammone, Investor Relations • Results Overview ◦ Lee Chen, CEO, President and Founder • 3Q 2019 Financial Results & Business Outlook ◦ Tom Constantino, CFO • Market Overview ◦ Chris White, EVP WW Sales • Q&A: Lee Chen, Tom Constantino, and Chris White 3

THE A10 VISION Enabling intelligent automation to ensure business critical RELIABLE applications are responsive, SECURITY secure and always available ALWAYS 4

Lee Chen CEO, President and Founder Reliable Security Always™

Q3’19 COMPANY UPDATE • Delivering Results ◦ 3Q results: Above the midpoint of guidance on revenue, top-line grew 7% sequentially, improved profitability (adjusted EBITDA of $4.0M) on lower levels of OpEx ◦ Strong engagement with customers who are adopting our secure application services for multi-cloud and 5G environments ◦ Q4 guidance: Forecasting another sequential increase in revenue • Strategy Committee of the Board of Directors ◦ Continues to evaluate opportunities to maximize shareholder value • CEO Search ◦ Company continues to evaluate candidates ◦ A10 has full commitment of Lee Chen through transition to eventual successor 6

REASONS FOR OPTIMISM INTO 2020 • Greater confidence in ability to navigate effectively through dynamic business environment • Client expansions in 5G infrastructure deployments ◦ Notable wins in South Korea, Japan, and Middle East • Mix shift with respect to high margin recurring revenue ◦ Targeting ~$100M recurring high-margin maintenance/subscription revenue in 2020 ◦ This revenue stream is faster growing and has better visibility vs. episodic hardware product sales 7

Tom Constantino CFO Reliable Security Always™

FINANCIAL PROFILE Reliable Security Always™

REVENUE $Millions Q3’19 Revenue: $52.8M 7% Q/Q $227 $235 $232 $196 $180 2014 2015 2016 2017 2018 10 The company adopted ASC 606 accounting standard effective January 1, 2018, all prior periods are based on ASC 605 standard.

REVENUE BY PRODUCT AND SERVICE $Millions $235 $232 $227 $196 3Q 2019 $52.8 million $180 33% 36% 38% 31% 25% 43% 67% 64% 75% 69% 62% 57% 2014 2015 2016 2017 2018 Product Service 11 The company adopted ASC 606 accounting standard effective January 1, 2018, all prior periods are based on ASC 605 standard.

REVENUE BY GEOGRAPHY $Millions $235 $232 $227 3Q 2019 2% 3% 4% $196 10% 12% 12% $52.8 million $180 3% 13% 14% 4% 14% 16% 11% 6% 12% 11% 23% 22% 12% 24% 18% 37% 25% 16% $56 53% 51% 49% 45% 48% 29% 2014 2015 2016 2017 2018 United States Japan APAC ex Japan EMEA Other 12 The company adopted ASC 606 accounting standard effective January 1, 2018, all prior periods are based on ASC 605 standard.

REVENUE BY CUSTOMER VERTICAL $Millions $227 $235 $232 14% $196 11% 18% 3Q 2019 $180 $52.8 million 10% 8% 41% 39% 39% 12% 45% 43% 50% 38% 48% 47% 50% 46% 43% 2014 2015 2016 2017 2018 SP Enterprise Web Giant 13 The company adopted ASC 606 accounting standard effective January 1, 2018, all prior periods are based on ASC 605 standard.

FINANCIAL PERFORMANCE HIGHLIGHTS $ Millions (except EPS) Income Statement Summary: Q3’19 Q3’18 Revenue $52.8 $ 60.5 Gross Margin % 78.1% 78.8% Operating Margin % 3.5% 4.2% Adjusted EBITDA $4.0 $4.2 EPS $0.02 $ 0.03 Balance Sheet & Cash Flow Summary: Q3’19 Q3’18 Cash & Marketable Security $122.6 $ 123.6 Accounts Receivable $45.4 $ 51.1 Deferred Revenue $98.1 $ 94.9 Debt - - Free Cash Flow $3.0 $ (3.9) Numbers may not sum due to rounding. Please refer to the supplemental financials posted the “Investor Relations” section of the A10 Networks website at investors.a10networks.com Gross Margin, 14 Operating Margin, Adjusted EBITDA and EPS are Non-GAAP Financial Measures. See Appendix for reconciliation to most comparable GAAP financial measures. The company adopted ASC 606 accounting standard effective January 1, 2018, all prior periods are based on ASC 605 standard.

BUSINESS OUTLOOK FOR Q4’19 • Revenue in the range of $55M to $59M, sequential growth of 8% at midpoint • Non-GAAP gross margin in the range of 76% to 78% • Non-GAAP operating expenses in the range of $39M to $40M, excluding severance and restructuring charges • Adjusted EBITDA in the range of $5.4M to $8.2M • Global workforce reduction of 5% driven by continuous focus on business optimization and overall profitability • Related severance and restructuring charges of approximately $2M • Non-GAAP EPS between $0.04 and $0.08 assuming approximately 80M diluted shares 15

Chris White EVP, WW Sales Reliable Security Always™

MARKET SUMMARY • North America ◦ NA revenue grew 28% QoQ and was the biggest driver of 7% overall sequential growth ◦ Large deals within Enterprise and Web Giant verticals continue to be delayed ◦ We are seeing increased traction from smaller-sized deals within our strategic NA accounts, positioning A10 for another QoQ increase in revenue in Q4’19 • 5G Security ◦ Land and expand continuing with customers who have selected A10 over the past year ◦ Received Winners’ Circle: Leaders’ Board Award from Intel for 5G security and NFVi innovation ◦ Continued focus on 5G security solutions (e.g. we saw significant expansion with a large carrier in the Middle East) • International ◦ Stable product bookings both YoY and QoQ ◦ Strong product revenue growth in Japan and Latin America • Added 185 new customers, up 5% YTD 17

HIGHLIGHTED CUSTOMER ENGAGEMENTS • Multi-million dollar competitive • New multi-million dollar • Follow-on 5G orders with leading win with North America engagement with large EMEA mobile providers in South Korea Broadband giant mobile provider to support upcoming 5G rollout 18

QUESTION & ANSWER SESSION Lee Chen Tom Constantino Chris White Founder & CEO CFO EVP, WW Sales 19

APPENDIX Reliable Security Always™

GAAP TO NON-GAAP % of Revenue except EPS Q3'19 Q3'19 YTD Q3'18 Q3'18 YTD Gross Margin % - GAAP 77.4 % 76.7 % 78.5 % 77.6 % Stock-based Compensation 0.6 % 0.7 % 0.3 % 0.7 % Gross Margin % - Non-GAAP 78.1 % 77.5 % 78.8 % 78.4 % EPS $ - GAAP $ 0.00 $ (0.24) $ (0.02) $ (0.36) Stock-based compensation $ 0.05 $ 0.16 $ 0.03 $ 0.18 Litigation and investigation expense (benefit) $ (0.03) $ (0.01) $ 0.02 $ 0.12 Amortization expense related to acquisition $ 0.00 $ 0.01 $ 0.00 $ 0.01 EPS $ - Non-GAAP $ 0.02 $ (0.08) $ 0.03 $ (0.04) Numbers may not sum due to rounding. EPS data is presented on a basic and diluted basis. Please refer to the supplemental financials posted the “Investor Relations” section of the A10 Networks website at 21 investors.a10networks.com The company adopted ASC 606 accounting standard effective January 1, 2018, all prior periods are based on ASC 605 standard.

GAAP TO NON-GAAP $ Millions Q3'19 Q3'19 YTD Q3'18 Q3'18 YTD Total operating expenses $ - GAAP $ 40.7 $ 134.0 $ 49.1 $ 157.6 Stock-based compensation (3.2) (11.3) (2.1) (11.8) Litigation and investigation (expense) benefit 2.2 $ 1.1 (1.5) (9.0) Amortization expense related to acquisition (0.3) $ (0.8) (0.3) (0.8) Total operating expenses $ - Non-GAAP $ 39.4 $ 123.0 $ 45.1 $ 136.0 % of Revenue Total operating expenses % - GAAP 77 % 88 % 81 % 92 % Stock-based compensation (6)% (7)% (4)% (7)% Litigation and investigation (expense) benefit 4 % 1 % (3)% (5)% Amortization expense related to acquisition (0)% (0)% (0)% (0)% Total operating expenses % - Non-GAAP 75 % 81 % 75 % 80 % Numbers may not sum due to rounding. Please refer to the supplemental financials posted the “Investor Relations” section of the A10 Networks website at investors.a10networks.com 22 The company adopted ASC 606 accounting standard effective January 1, 2018, all prior periods are based on ASC 605 standard.

GAAP TO NON-GAAP $ Millions Q3'19 Q3'19 YTD Q3'18 Q3'18 YTD Income (loss) from operations $ - GAAP $ 0.2 $ (17.2) $ (1.6) $ (25.3) Stock-based compensation 3.5 12.5 2.3 13.1 Litigation and investigation (expense) benefit (2.2) (1.1) 1.5 9.0 Amortization expense related to acquisition 0.3 0.8 0.3 0.8 Income (loss) from operations $ - Non-GAAP $ 1.8 $ (5.1) $ 2.5 $ (2.4) % of Revenue Income (loss) from operations % - GAAP 0 % (11)% (3)% (15)% Stock-based compensation 7 % 8 % 4 % 9 % Litigation and investigation (expense) benefit (4)% (1)% 3 % 5 % Amortization expense related to acquisition 0 % 0 % 0 % 0 % Income (loss) from operations % - Non-GAAP 3 % (3)% 4 % (1)% Numbers may not sum due to rounding. Please refer to the supplemental financials posted the “Investor Relations” section of the A10 Networks website at investors.a10networks.com 23 The company adopted ASC 606 accounting standard effective January 1, 2018, all prior periods are based on ASC 605 standard.

THANK YOU RELIABLE SECURITY ALWAYS INVESTORS@A10NETWORKS.COM