Definition of 'Market Letter'
A short publication that informs investors and other stakeholders, often via paid subscription, about a particular category of investments. For example, some newsletter focus on growth stocks while others specialize in the energy sector and recommend particular holdings to its readers. A real estate market letter would provide data and commentary on some segment of the real estate market, like the housing market or commercial real estate.
Investopedia explains 'Market Letter'
The investment advice provided in market newsletters is not necessarily sound. Some financial service providers rate various market letters by evaluating how well investors would fare if they followed the advice of those letters. They have found that most letters underperform the market.
Not all market letters strictly provide investment advice. For example, some advertise automobiles and provide other information to Ferrari enthusiasts, while others focuses on biotechnology and pharmaceuticals.