Forget Fed—this is real stock driver: Strategist

Fed liftoff almost 'done deal' but markets will key off ECB: Pro

Investors continue to focus on global central bankers, but it's the European Central Bank not the Federal Reserve that's really going to influence the markets, Jefferies Chief Market Strategist David Zervos said Wednesday.

The ECB on Thursday is expected to expand its quantitative easing program and cut its already negative deposit interest rate.

"I really don't think any of us are prepared for what it means to have a negative 40- or 50- ... basis-point deposit rate in a major currency," Zervos told CNBC's "Squawk Box." Such a move would send the strong dollar even higher "and I think European stocks rally," he said.

On Wednesday morning, the yield on German two-year bonds hit a record low of negative 0.432 percent.

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The expected moves by the ECB would be in the opposite of direction of an expected Fed hike in U.S. rates at its Dec. 15-16 meeting.

"The [Fed] liftoff story to me is almost a done deal. It's only a question of how they couch it in language," said Zervos. He said Fed Chair Janet Yellen will likely stress that any tightening would be gradual.

Yellen is set to speak at the Economic Club of Washington at 12:25 p.m. ET Wednesday afternoon, and is scheduled to testify before Congress on Thursday morning.

In a speech Wednesday morning, Atlanta Fed President Dennis Lockhart said there's a "compelling" case for a rate hike at the meeting, absence any drastic changes in the economic picture. The Labor Department's November employment report comes out Friday.

Lockhart, considered a centrist, is a voting member on the central bank's policymaking committee this year.

Read MoreFed's Lockhart: Upcoming FOMC meeting may be 'historic'

Zervos said it's "highly unlikely at this stage" that any big negative economic surprise would keep the Fed from moving rates higher.

But with the ECB easing, he continued, the Fed won't be compelled to rise rates much, and that would serve as a net-positive U.S. stocks.

In a separate interview, Charles Schwab Chief Investment Strategist Liz Ann Sonders said she expects the Fed will hike rates 25 basis points at the meeting.

"You would have to see an extraordinary span of weakness, including Friday's jobs report I think, for the Fed to kind of turn tail on that expectation," she told CNBC. "I think generally the domestic side of the economy is in good shape. But we're still at a below-trend growth rate."

As for the stock market, Sonders sees 2016 playing in similar fashion to this year: not much headway, greater volatility, and a risk of a pull back. "At this point when I look into 2016 ... I still think we're secular bull market, but we're in a more mature phase."