Economic Downturn Impact: Boston Properties is highly sensitive to general economic conditions, as recessions or economic slowdowns can lead to decreased demand for office space, lower rental rates, and higher vacancy rates across its portfolio.

Interest Rate Fluctuations: Rising interest rates increase BXP's borrowing costs for existing variable-rate debt and future financing, potentially reducing property valuations and making acquisitions or development projects less attractive.

Tenant Leasing & Retention Challenges: The company faces ongoing risk in attracting and retaining high-quality tenants, especially during periods of market softness or significant lease expirations, which can lead to extended vacancies and lower rental income.