The financial markets are expecting the US FED, the central bank, to raise interest rates, or the federal funds rate, the first time since the financial crisis of 2007. The federal funds rate has been to zero in order to stimulate the economy. Lowering interest rates is a monetary policy that all central banks follow, and is an expansive monetary policy, in order for the economy to grow above potential. The federal funds rate is the interest rate that commercial banks borrow overnight among each other.
The US central bank's function is one of a dual mandate. That is, its function is to keep inflation under control, and at the same time keep unemployment at reasonable levels.
Here is a interesting article, published by the Washington Post, entitled "Everything you need to know about the federal reserve, and its expected rate hike". The link is https://www.washingtonpost.com/news/wonk/wp/2015/12/15/everything-you-need-to-know-about-the-federal-reserves-expected-interest-rate-hike/
I really recommend this reading. Increasing interest rates means reducing the money supply by shifting it to the left, thus affecting GDP, meaning lower growth.
On the map above, it depicts the federal reserve regions in the United States.
