According to Morgan Stanley, the S&P 500 will fall to a new low in early 2003. In the opinion of the bank's leading stock picker Mike Wilson, it will prove to be a good buying opportunity, he said in a conversation with CNBC.

The index has lost about 17% this year amid persistently high inflation and aggressive rate hikes by the Fed. It has been bearish since June. Wilson, however, is optimistic about next year, believing the downturn in the U.S. stock market will come to an end. Nevertheless, he called investors' earnings expectations overstated - they exceeded the real estimate by 20%. Still, Wilson expects the index to move up by the end of next year and be at 3,900 - he said his assessment focuses on expectations for higher volatility, rather than negative stock performance. However, he added that 2023 promises to be a challenging year for the stock market.