Strategists at Morgan Stanley have cautioned that U.S. equities are vulnerable to additional energy price spikes and heightened bond market turbulence, suggesting the S&P 500 could shed as much as 7% under such conditions. The team, led by Michael Wilson, noted that while robust corporate earnings have so far helped shares withstand higher bond yields, the index's valuation has slipped to its lowest level since March over the past four months.

Wilson wrote in a report, "Should further tightening in financial conditions and/or a significant surge in energy prices worsen the valuation pullback, we believe the S&P 500 could fall to as low as 7,100 points before the bull market resumes by year-end." That level implies a 7% drop from the index's closing price last Friday. Wilson also anticipates rising volatility heading into the November midterm elections, but ultimately he expects solid earnings growth to drive a year-end rally toward his 8,000-point target, which would represent a gain of nearly 5% from current levels.

The S&P 500 has been choppy since hitting an all-time high in mid-August, as concerns over the inflation outlook persist while the 10-year Treasury yield hovers near 5%. WTI crude has retreated below $100 per barrel but remains 43% higher than its July low. The Federal Reserve delivered its first rate hike in three years last week, yet the central bank's commitment to fighting inflation continues to keep investors bullish.

The benchmark index is currently only about 2% below its peak, supported by one of the best earnings seasons on record for the second quarter. Market strategists at firms including JPMorgan and Goldman Sachs have also indicated that healthy profits should keep favoring equities, although the team at Bank of America warns that investor positioning remains overly optimistic as profit growth slows.

Morgan Stanley's Wilson has been one of the most bullish voices on U.S. stocks this year. He reiterated his recommendation for large-cap quality names and noted that momentum is building in service-oriented, asset-light industries.