With nearly 100 years of combined experience...

Mitch Cox Realtor, Inc. has been a staple in the business and real estate communities of the Tri-Cities Region for the past 40 years. This positions us uniquely in the marketplace to provide our clients with the market knowledge and insight critical to any commercial real estate transaction. We strive every day to exceed our clients’ expectations in order to help them best meet their strategic objectives.

Meet Our Brokerage Team

John Speropulos, CCIM SIOR

John Speropulos, CCIM SIOR

Development Partner, President of Mitch Cox Realtor, Inc.

With more than seventeen years of experience in the real estate industry, John leads the commercial division of Mitch Cox Companies and is President of Mitch Cox Realtor, Inc. In his career, John has successfully represented local, regional, and national clients. He also manages a portfolio of more than 1,100,000 square feet of commercial real estate in the Tri-Cities. John has two Bachelor of Business Administration degrees from East Tennessee State University (one with a major in Accounting, the other with a major in Finance - Real Estate), and is a licensed Commercial Real Estate Agent in Tennessee & North Carolina.

As a Certified Commercial Investment Member (CCIM), he is recognized as an expert in commercial and investment real estate by the CCIM Institute. Only 6% of commercial real estate practitioners nationwide hold the CCIM designation.

John is deemed a Specialist in the Office Market and has been conferred the designation of SIOR by the Society of Industrial and Office Realtors. Real estate professionals who have earned the SIOR designation are recognized as the most capable and experienced brokerage practitioners in any market.

The Mountain States Foundation named John the recipient of the 2015 Spirit Award. John has also received the National Commercial Award for Excellence in the Commercial Real Estate Industry from the National Association of Realtors and the Mark Keesecker Humanitarian Award from the Northeast Tennessee Association of Realtors. He was recognized as a 40 Under Forty by the Business Journal of Tri-Cities and has been inducted into the ETSU Hall of Fame.

John is a Past Member and Chairman of the Advisory Board for Jefferson Federal Bank's Tri-Cities Division. He has served as a Past Director of State of Franklin Savings Bank; a Past Director of Eastman Credit Union; a Trustee and Past Chairman of Mountain States Foundation; has served on the Investment Committee and Relationship Committee of Mountain States Health Alliance and presently serves on their Finance Committee; a Past Chairman of Young Life of Upper East Tennessee; is a Member of the International Council of Shopping Centers; a Member of the National Association of Realtors; a Member and Past President of the Tri-Cities Chapter of CCIM; serves as Admissions Chairman of the East Tennessee Chapter of SIOR; serves on the President's Executive Council of Milligan College; serves as a member of the East Tennessee State University Foundation; serves on the Northeast State Community College Foundation; and serves as a Member and Elder of Redeemer Community Church.

Marc Murphy, CCIM

Marc Murphy, CCIM

Vice President of Mitch Cox Realtor, Inc.

With over sixteen years of commercial real estate experience and over 1,000 transactions completed, Marc currently serves as Vice President of Brokerage for Mitch Cox Realtor, Inc., representing Sellers/Landlord and Buyers/Tenants with equal diligence and commitment. Marc is a licensed Commercial Real Estate Agent in Tennessee & North Carolina and a native of Johnson City, TN. He earned his Bachelor of Business Administration in Finance with a concentration in Real Estate from East Tennessee State University. He specializes in investment sales/acquisitions along with the leasing and selling of retail, office and industrial properties.

Marc has been conferred the Certified Commercial Investment Member (CCIM) designation from the CCIM Institute. A CCIM is a recognized expert in the commercial and investment real estate industry. Designees have completed a curriculum that covers essential CCIM skill sets including ethics, interest-based negotiation, financial analysis, market analysis, user decision analysis, and investment analysis for commercial investment real estate. CCIMs have completed a portfolio demonstrating the depth of their commercial real estate experience. Finally, they have demonstrated their proficiency in the CCIM skill sets by successfully completing a comprehensive examination.

Marc is a member of the International Council of Shopping Centers; is a Member of the East Tennessee Chapter of CCIM; is a Current & Past Member of the Commercial MLS Committee for the Northeast Tennessee Association of Realtors; He is a past Board Member for Summit Leadership Foundation, a non-profit ministry whose mission is to develop & connect Christian leaders as well as to create relational hubs for connecting, consulting, coaching, & caring; is the past Chair of the Facilities Committee & the Facilities Acquisition Taskforce for Summit Leadership Foundation; is a Past President of the Tri Cities Division of the East Tennessee Chapter of CCIM where he also served on the Executive Committee as Communications Chair & Education/Scholarship Co-Chair; and is a past Advisory Board Member for generatioNext, Magazine For Young Professionals.

Shannon K. Castillo

Shannon K. Castillo

Affiliate Broker

Shannon joined Mitch Cox Companies in January of 2014 as Affiliate Broker for Mitch Cox Realtor and as Assistant to our founder Mitch Cox. She is a licensed Commercial Real Estate Agent in Tennessee.

She has over 12 years of award winning sales experience and joins the staff following her position as Director of Redevelopment for Washington County Economic Development Council. In that role, she recruited new businesses, worked closely with the city officials of Johnson City, developed relationships with downtown business owners, and worked on the tax increment financing for downtown Johnson City. Her experience in sales, customer service, and her time spent in public service in economic development make her skills uniquely valuable for commercial real estate.

Shannon is active in the community as member of Redeemer Community Church, Secretary of the board for the Friends of Olde Downtowne, member of the planning committee for the Blue Plum Music and Arts Festival for downtown Johnson City, and member of the 2013 fundraising committee for the United Way of Washington County, TN. Shannon was also recognized as a 40 Under Forty recipient by The Business Journal of Tricities, Tennessee/Virginia.

Shannon is a native of Ohio and a Magna Cum Laude graduate of Milligan College with Bachelor of Science degree in Business and Communications. She has lived in Johnson City for over 20 years with her husband and two daughters.

She loves Downtown Johnson City, cooking spaghetti for 100 people, and renovating her 1890’s era home.

Contact her on twitter @thinkshannon.


Mitch Cox Realtor, Inc. is licensed in the state of Tennessee. Our team of agents represent sellers, landlords, buyers, tenants and real estate investors with unmatched diligence and commitment – our reputation depends on it. We listen carefully to our clients and ask critical questions in order to fully understand their needs. Having gained perspective from both sides of the table in the countless transactions we have completed gives us unique insight and an edge that has greatly benefited our clients. Our service offering are as follows:

Seller & Landlord Representation

Whether your goal is to sell or lease your property, the team at Mitch Cox Realtor, Inc. has the extensive local market knowledge and deep industry connections to deliver optimal results. Our vast network of relationships and marketing avenues allows us to give your property maximum market exposure. We will position your property in order to maximize value and minimize time on market.

Buyer & Tenant Representation

Representing buyers and tenants in the marketplace is one of our specialties. Whether establishing a new presence in the region, growing your number of locations, expanding, contracting or simply relocating, Mitch Cox Realtor, Inc. has the site-selection experience and knowledge to assist you. With an exceptional ability to think inside and outside the box, our team will identify the properties that meet your needs, evaluate the financial impact of your various options, negotiate aggressively and effectively on your behalf and assist in avoiding the pitfalls that can come with lack of professional representation.

Investment Sales & Acquisition

As seasoned investors ourselves, we understand the vast differences between buying and selling income-producing investment properties in comparison to owner/user transactions. We work in tandem with our clients’ attorneys and accountants, truly becoming a member of our clients’ acquisition or disposition teams, to help our clients fully understand what to expect after closing and how to maximize their returns.

View Previously Leased / Sold Properties

2304 Silverdale Drive, Ste. 200
Johnson City, TN 37601

P (423) 282-6582
F (423) 282-5903


Monday – Friday, 8:00 am – 5:00 pm


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