Wall Street analysts are broadly bullish on Walmart's shares. Credit: Getty ImagesKey TakeawaysOppenheimer downgraded Walmart stock to a neutral rating, citing reduced outperformance potential. Analysts highlighted U.S. pharmacy revenue headwinds, valuation concerns, and overly optimistic Street forecasts. Oppenheimer analysts on Tuesday downgraded Walmart (WMT) stock to a neutral "perform" rating, withdrawing a $140 per share price target that represented a 26% premium to yesterday's close around $111 and was roughly in line with the Visible Alpha mean. "Although we are stepping to the sidelines, we still remain very upbeat on [Walmart's] longer-term prospects," the analysts wrote.