
Extract the answer to the question from the following context.
Question: What is the main market for trading stock called in Europe?
Context: Estonia has had a market economy since the end of the 1990s and one of the highest per capita income levels in Eastern Europe. Proximity to the Scandinavian markets, its location between the East and West, competitive cost structure and a highly skilled labour force have been the major Estonian comparative advantages in the beginning of the 2000s (decade). As the largest city, Tallinn has emerged as a financial centre and the Tallinn Stock Exchange joined recently with the OMX system. The current government has pursued tight fiscal policies, resulting in balanced budgets and low public debt.

OMX system
