CoreSite Realty Corp: management transactions · United States · SEC (Form 4)

About CoreSite Realty Corp

CoreSite Realty Corp. (ticker: COR) is a U.S.-based digital infrastructure company focused on colocation data centers. For international investors, an important nuance is that CoreSite is no longer a standalone publicly traded company: it was acquired by American Tower in December 2021. Its legacy listing was on the NYSE, and the business remains an important operating platform within American Tower’s U.S. data center portfolio. CoreSite is headquartered in Denver, Colorado, United States. Founded in 2001 as CRG West, CoreSite built its franchise around a clear value proposition: provide highly interconnected, carrier-dense data centers for enterprises, cloud providers, network operators, and digital businesses. Today the company owns and operates 30 network-dense, cloud-enabled data centers across 11 strategic U.S. markets, totaling more than 4.8 million square feet. It also reports more than 44,000 customer interconnections and over 500 network providers. The company’s differentiation is not simply physical capacity; it is the interconnection ecosystem, including direct access to major cloud platforms and its software-defined networking platform, Open Cloud Exchange® (OCX). CoreSite’s main business lines include high-density colocation, network interconnection, native cloud on-ramps, and hybrid/multicloud infrastructure solutions. These services are designed for mission-critical workloads that require low latency, strong resilience, and efficient connectivity between enterprise systems, cloud services, and network partners. CoreSite is particularly relevant for data-intensive and compute-intensive use cases, including modern AI and HPC deployments. Its portfolio spans key U.S. hubs such as Los Angeles, Silicon Valley, Chicago, New York, Boston, Northern Virginia, Denver, and Miami. From a competitive standpoint, CoreSite occupies a premium niche in the data center market. It competes in a space shaped by major peers such as Equinix and Digital Realty, but its emphasis on urban campuses, cross-connect density, and cloud adjacency gives it a distinct positioning. The American Tower ownership structure also adds strategic and financial support, broadening CoreSite’s reach within a larger real-estate and connectivity ecosystem. Recent developments highlight the company’s exposure to structural demand tailwinds. In 2025 and 2026, CoreSite announced new and expanded capacity, including its NY3 facility in the New York metro area, continued development of the DE3 campus in Denver, upgraded cloud connectivity on OCX, and additional high-speed networking capabilities such as 400G services. The company has also emphasized AI-ready infrastructure and has been recognized in industry reports and partner certifications. For investors following U.S. NYSE/NASDAQ infrastructure names, CoreSite remains a relevant reference point in the colocation and interconnection market, especially where AI, hybrid IT, and low-latency connectivity are central to customer demand.