“Among the investors there is a feeling of nervousness and confusion. The decision of Yellen not addressed the issue of the Fed meeting in Jackson last month left information vacuum that forces the markets to interpret the situation themselves, which creates instability,” said Thorsen Slok, chief economist at Deutsche Bank.

Earlier in the year signals the Fed led many analysts to expect an increase in June, but the appreciation of the dollar change the position of the central bank. Uncertainty is exacerbated by the different positions of the members of the leadership of the Fed on the right time for raising interest rates from near-zero levels, which have not changed since the end of 2008

Besides market instability and expensive dollar falling commodity prices and lower inflation expectations have also been cited as possible reasons for the Fed to not rush into changes in monetary policy. To this is added the appeals of institutions like the International Monetary Fund and the World Bank rates can not be changed given the existing risks. While central bankers from developing countries insist the Fed to raise interest rates and to end the uncertainty that leads to capital outflows and depreciation of currencies in their countries.

According to Nicholas Gardsayd, senior fund manager at JPMorgan Asset Management, the Fed will raise interest rates, but will also stress that the subsequent tightening of policy will be applied with extreme caution. “Perhaps the Fed will lower its forecast for future interest rates rise. The message to be sent is more important part of the Fed meeting,” he said.