The Federal Reserve is heading into this week’s pivotal interest rate-setting meeting with financial markets and Wall Street analysts deeply split over whether it will tighten monetary policy following weeks of mixed signals from the central bank.

Conflicting messages from a divided body of Fed officials mean futures traders are betting against the possibility of a rate increase, while nearly half of economists surveyed by Bloomberg expect the Fed to pull the trigger next week. Other analysts think the US central bank could hold steady until 2016.

Torsten Sl?k, chief international economist at Deutsche Bank, said he was picking up “frustration and confusion” among investors. The uncertainty presents Fed chair Janet Yellenwith a leadership test as she presides over a hugely contentious decision on Thursday, amid clashing data and heavy lobbying from across the globe.