What happened

Boston Beer (SAM -17.78%) shareholders beat a rallying market last month. The stock rose 17% in March, compared to a 4.2% increase in the S&P 500, according to data provided by S&P Global Market Intelligence.

With that, the alcoholic-beverage specialist is up more than 10% so far in 2021 after having trounced the market last year.

Two people clinking beer glasses in a toast.

Image source: Getty Images.

So what

The stock gained more love from Wall Street pros in March, with an analyst at Goldman Sachs issuing an elevated price target late in the month. Investors have been impressed with Boston Beer's market-trouncing sales growth despite some difficult selling conditions. Depletions, a measure of consumption, jumped 37% last year thanks to booming demand for the Truly and Twisted Tea brands. Expectations are high for the company to repeat that stellar performance in 2021.

Now what

With an earnings report likely in late April, investors won't have to wait long to learn whether Boston Beer is meeting those goals. That announcement will add clarity to the company's growth expectations. In its most recent guidance, management gave a wide estimate for depletions, projecting an increase of between 35% and 45% in 2021.

An updated forecast near the high end of that range would support the stock's rally. But there are also big risks to the bullish thesis, including mounting competition in the hard seltzer space and weak profit margins as Boston Beer prioritizes growth over earnings.