Jerome Powell, chairman of the U.S. Federal Reserve, speaks during a news conference following a Federal Open Market Committee (FOMC) meeting in Washington, D.C., Sept. 26, 2018. Andrew Harrer | Bloomberg | Getty Images

Wall Street's eyes will be glued on Federal Reserve Chairman Jerome Powell when he delivers Wednesday what will be the most critical speech of his short time leading the central bank. The remarks will come amid sharp market tumult that began after comments he made in early October indicating the Fed was not close to stopping interest rate increases. Since then, stocks have wobbled around correction levels, credit markets have shown considerable signs of stress and investors have begun to bet that the Fed will ease its hawkish stance. For Powell, who took the helm in February, the stakes are high as he likely will signal a cautious approach to future rate hikes without explicitly indicating a change in plans from earlier projections.

The speech, to be delivered shortly after noon ET at the Economic Club of New York, "will continue the process of softening the Fed's message" said Krishna Guha, head of global policy and central bank strategy at Evercore ISI. Those hoping for more, though, could be disappointed. "In our view the likelihood that Powell will signal that the Fed is preparing to stop and take a timeout on rates is very low," Guha said in a note, adding that the speech "may be the most consequential of his tenure to date." Powell likely will reiterate that the Fed "will continuously reassess the extent of the rate path," an important point amid concerns over global growth, an escalating trade war and a possible slowdown in the U.S., Guha added. Watch: How the Fed could cause the next recession, according to Gary Shilling

"This might reasonably be interpreted as implying that if current conditions — tighter financial conditions, weaker growth including in China and Europe, elevated geopolitical risks – continue to prevail, the Fed is likely to shave a bit off the cumulative rate hikes planned through end 2020," he said. As things stand, the Federal Open Market Committee is planning to raise its benchmark short-term rate a quarter-point in December, a move to which the market has assigned a 79 percent probability. Things get sketchy from there, though. While Federal Open Market Committee members have pointed to three increases in 2019, the market is only anticipating one. That divergence has come even though multiple FOMC members have said continued gradual rate hikes are likely if economic conditions persist. With Powell unlikely to indicate an explicit change of direction, there are expectations that he at least may indicate a slower rate of increases rather than an outright pause during the current volatility and uncertainty. "We think Powell is a solid pragmatist who made one significant error this fall — declaring that 'we're a long way' from a neutral Fed funds rate," wrote Greg Valliere, chief global strategist at Horizon Investments. "That spooked the markets, which weren't prepared for such a hawkish pronouncement. The markets are looking for assurances that the Fed won't move too quickly — and Powell may offer some assurances on Wednesday."