Q3 2021 Investor Presentation – November 2021

ONE DATA CENTER PROVIDER.

EVERYTHING YOU NEED.

Q3 2021 Investor Presentation

November 2021

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Forward Looking Statements

This investor presentation may contain forward-looking statements within the meaning of the federal securities laws. Forward-looking statements relate to expectations, beliefs, projections, future plans and strategies, anticipated events or trends and similar expressions concerning matters that are not historical facts. In some cases, you can identify forward- looking statements by the use of forward-looking terminology such as "believes," "expects," "may," "will," "should," "seeks," "approximately," "intends," "plans," "pro forma," "estimates" or "anticipates" or the negative of these words and phrases or similar words or phrases that are predictions of or indicate future events or trends and that do not relate solely to historical matters. Forward-looking statements involve known and unknown risks, uncertainties, assumptions and contingencies, many of which are beyond CoreSite's control, that may cause actual results to differ significantly from those expressed in any forward-looking statement. These risks include, without limitation: the geographic concentration of CoreSite's data centers in certain markets and any adverse developments in local economic conditions or the level of supply of or demand for data center space in these markets; fluctuations in interest rates and increased operating costs; difficulties in identifying properties to acquire and completing acquisitions; significant industry competition, including indirect competition from cloud service providers; failure to obtain necessary outside financing; the ability to service existing debt; the failure to qualify or maintain its status as a real estate investment trust ("REIT"); financial market fluctuations; changes in real estate and zoning laws and increases in real property tax rates; the effects on our business operations, demand for our services and general economic conditions resulting from the spread of the novel coronavirus ("COVID-19") in our markets, as well as orders, directives and legislative action by local, state and federal governments in response to such spread of COVID-19; and other factors affecting the real estate industry generally. All forward-looking statements reflect CoreSite's good faith beliefs, assumptions and expectations, but they are not guarantees of future performance. Furthermore, CoreSite disclaims any obligation to publicly update or revise any forward-looking statement to reflect changes in underlying assumptions or factors, of new information, data or methods, future events or other changes. For a further discussion of these and other factors that could cause CoreSite's future results to differ materially from any forward-looking statements, see the section entitled "Risk Factors" in its most recent annual report on Form 10-K, and other risks described in documents subsequently filed by CoreSite from time to time with the Securities and Exchange Commission.

ONE DATA CENTER PROVIDER. EVERYTHING YOU NEED.

© 2021, CoreSite, L.L.C. All Rights Reserved.

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Our Purpose, Focus and Strategy

CoreSite delivers value to both customers and shareholders by creating and expanding high-uptime data center campuses, which provide a high-performance,cost-saving ecosystem for efficient interoperability between enterprises, digital content providers, network service providers, and cloud and IT service providers.

		Cloud Providers
Networks		35%		Enterprises
24%				41%

Customer Vertical and Percentage of Total Data Center Annualized Rent as of 9/30/2021

ONE DATA CENTER PROVIDER. EVERYTHING YOU NEED.

© 2021, CoreSite, L.L.C. All Rights Reserved.

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CoreSite at a Glance

Delivering network-dense,edge-market data centers, with rich ecosystems

2001	480+	4.6+ Million
Year Founded	Professionals	Gross NRSF

1,370+	600+	440+	330+
Customers	Enterprise and	Network Service	Cloud and IT
	Digital Content	Providers	Service Providers

100%	25	8	32,000+
Uptime SLA	Operational	Markets	Customer
	Data Centers		Interconnections
	ONE DATA CENTER PROVIDER. EVERYTHING YOU NEED.	© 2021, CoreSite, L.L.C. All Rights Reserved. 4

High Quality, Strategically Located, Cloud Access

Our customers can reach 22% of the U.S. population representing 31% of U.S. GDP and

have the ability to cover more than 75% of U.S. businesses within 5 milliseconds with performance-sensitive applications and products across our 8 markets.

Market	# of Networks
Los Angeles	290+
Denver	95+
Northern Virginia / D.C.	65+
San Francisco Bay	65+
New York / New Jersey	60+
Chicago	40+
Boston	35+
Miami	20+

CLOUD SERVICES

In addition to direct connect markets listed to the right, Amazon, Microsoft, Google, Alibaba Cloud, IBM Cloud and Oracle FastConnect can all be accessed through the CoreSite Open Cloud Exchange® in all eight of our markets.

NATIVE CLOUD ON-RAMPS

AWS Direct Connect: LA, VA, SV, NY, DE

Google Cloud Interconnect: LA, VA, SV, CH

Microsoft Azure ExpressRoute: LA, VA, SV, CH, DE

Oracle FastConnect: LA, VA, CH

IBM Cloud Direct Link: LA, VA, DE

Alibaba Cloud: VA

CoreSite owns approximately 93% of the NRSF comprising its data centers.

ONE DATA CENTER PROVIDER. EVERYTHING YOU NEED.

© 2021, CoreSite, L.L.C. All Rights Reserved.

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