With a GDP of US$182 billion in 2008, Istanbul ranked 34th among the world's urban areas in terms of gross domestic product. Istanbul is responsible for27 percent of Turkey's GDP, with 20 percent of the country's industrial labor force residing in the city. Its GDP per capita and productivity are greater than their national averages by 70 percent and50 percent, respectively, owing in part to the focus on high-value-added activities. With its high population and significant contribution to the Turkish economy, Istanbul is responsible for two-fifths of the nation's tax revenue. That includes the taxes of thirty billionaires based in Istanbul, the fifth-highest number among cities around the world.
As expected for a city of its size, Istanbul has a diverse industrial economy, producing commodities as varied as olive oil, tobacco, transport vehicles, and electronics. Despite having a focus on high-value-added work, its low-value-added manufacturing sector is substantial, representing just26 percent of Istanbul's GDP, but four-fifths of the city's total exports. In 2005, companies based in Istanbul produced exports worth US$41.4 billion and received imports totaling US$69.9 billion; these figures were equivalent to 57 percent and 60 percent, respectively, of the national totals.
Istanbul is home to Turkey's only securities market, the Istanbul Stock Exchange. Although it was originally established as the Ottoman Stock Exchange in 1866, its importance declined after theGreat Depression in the 1930s. It was ultimately reorganized into its current form at the start of 1986, following a series of governmental financial liberalization programs. During the 19th and early 20th centuries, BankalarCaddesi (Banks Street) in Galata was the financial center of the Ottoman Empire, where the Ottoman Stock Exchange was located. BankalarCaddesi continued to be Istanbul's main financial district until the 1990s, when most Turkish banks began moving their headquarters to
