It appears that investors have failed to realize that the "bear market" in stocks ended after Christmas Eve's washout on Wall Street, CNBC's Jim Cramer contended Monday.

"We came through a bear market," Cramer said on "Squawk on the Street," shortly after the opened lower. "I think people are still oblivious that the bear market ended on that horrible half-day" Dec. 24 session.

Stocks last month plunged in their worst Christmas Eve trading ever, with the sinking 2.7 percent and slipping into a bear market, which is defined as a decline in an index or asset of 20 percent or more from recent highs.

Since then, the S&P 500 has rallied nearly 10.5 percent through Friday's close. However, many analysts believe the market could still retest its lows, especially as earnings season kicks in.

Cramer has said he does not use the traditional definitions of a bear market and a correction — measured as a drop of 10 percent or more from recent highs — and instead focuses on individual stocks.

Cramer blames Jerome Powell for the stock market's losses late last year, arguing the Federal Reserve chairman stoked fears after his comments on Oct. 3 that rates were a "long way" from so-called neutral. The following month, Powell appeared to walk back those remarks, saying rates are "just below" neutral. Central bankers increased rates four times in 2018, and projected two more hikes this year.

However, on Jan. 4, Powell said central bankers "will be patient" on rates given continued muted inflation, touching off a strong rally of nearly 3.5 percent on the S&P 500 that day, and increases in four out of the next five sessions as of Friday.

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