The firm is bullish on the company's spiked seltzer brand Truly, citing its strong sales growth as a catalyst for the improved view despite rival spiked seltzer brand White Claw still holding 85% market share.
"Truly and Claw are now the law. Truly is far outpacing our estimates with additional room to run next year, even as White Claw remains the category leader," Guggenheim analyst Laurent Grandet wrote.
The price target is well ahead of Wall Street's consensus $361.43 price target and represents a potential 34% upside from the stock's closing price Friday of $345.48.
Boston Beer shares were up 3.15% to $356.38 on Monday.
The firm is also bullish on the company's third-quarter earnings estimate, raising its guidance to $3.27 a share from $2.87. The consensus is for Boston Beer to report earnings of $2.82 a share.
"We continue to think management's FY19 guidance is conservative, and we expect another "beat and raise" quarter when the company reports 3Q results," Grandet said.