The news conference Jerome Powell gave on Wednesday, his fourth as chairman of the Federal Reserve, was his most consequential to date, coming amid market turbulence and signs of an economic slowdown in the year ahead.

But his message — or at least the part of it that matters most for the direction of the economy and markets — wasn’t a simple one. It boils down to this:

The Fed still believes that the economy is basically sound, and that growth will continue in 2019 and beyond, albeit at a slower rate than in 2018. There were no signs that Mr. Powell and his colleagues are hitting the recession panic button presumably hidden somewhere in the Marriner S. Eccles Building.

That being the case, there was no reason not to follow through with the interest rate increase that had already been telegraphed.

But the choppy global economy and sell-off in stock and certain corporate debt markets has gotten Fed officials’ attention, and they’re open to the possibility that their optimism is misplaced. The officials are now thinking they should raise rates only twice next year, not three times as envisioned in September, and they’re prepared to throttle back further if events justify it.

Oh, but the effort to reduce the Fed’s multi-trillion-dollar portfolio of bonds, acquired during its post-crisis era of monetary interventionism, will continue on autopilot, no matter how much President Trump tweets his complaints about it (as he did Tuesday).

It’s a bit of a messy combination, which helps explain why stocks sold off as the news conference progressed.

Mr. Powell has emphasized that, with the economy relatively healthy, the Fed needs to make its policy moves responsive to incoming information, an approach of “data dependence.” This contrasts with his immediate predecessors, who stressed “forward guidance” — using explicit signals about future plans as a tool of policy.

“There’s a fairly high degree of uncertainty about both the path and the destination of any further increases,” Mr. Powell said in the news conference.