The gross domestic product of Guwahati metro was estimated at $1 billion in 2010. As a river port, Guwahati has traditionally been an important administrative and trading center. Separate income estimates are not yet available as city-level income estimation is not a traditional practice in India, and is not practiced in a systematic and continual manner. However, by looking at the agglomeration of activities and employment patterns it can be easily understandable that the city contributes a lion's share of the state's income.
The major economic activities are trade and commerce, transportation and services. Guwahati is the most important trade hub in the North Eastern Region. It is a major wholesale distribution center, a marketing hub, and also a retail hub of the region. The Guwahati Tea Auction Centre is one of the largest in the world. As in other cities, 'mall culture' is now invading Guwahati. Manufacturing is an important activity, although it is not comparable to those of India's rapidly growing industrial cities. The most important manufacturing industry in the city is the petroleum refinery of IOCL at Noonmati, which is known as Guwahati Refinery. The city contains the headquarters or regional offices of several manufacturing and business establishments, e.g., Numaligarh Refinery Limited (NRL). Bamunimaidam and Kalapahar are two major industrial estate of Guwahati. Guwahati is important for printing and publishing, as well as businesses related to electronic and print media. During the past two decades, businesses such as real estate development, finance, etc. have intensified. Retail and real estate have emerged as big players. Recent times have seen large scale retail chains such as Big Bazaar, Westside, Pantaloons, Salasar Mega Store, Hidesign, Wills Lifestyle, Levi Strauss & Co. had opened outlets in Guwahati. Guwahati is home to the Guwahati Stock Exchange (GSE). For the promotion of trade and industry of Assam there is a trade centre
