Amid Blackstone Group (BX - Get Report) Vice Chairman Byron Wien's 2018 prediction of a 10% pullback in the S&P 500, TheStreet's founder and Action Alerts PLUS Portfolio Manager Jim Cramer questions whether investors are ready for such a correction.

Even with a correction, Wien expects the S&P 500 to finish the year above 3,000. The S&P 500 crossed 2,700 on Wednesday. 

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