What: Shares of Boston Beer (SAM 0.77%) fell 13% Tuesday after analysts at two firms issued negative notes regarding the craft brewing specialist.

So what: Keep in mind Boston Beer most recently disappointed investors by turning in mixed fourth-quarter 2015 results and light guidance three weeks ago. Most notably, its founding chairman, Jim Koch, voiced his belief that Boston Beer has lost market share as new craft brewers enter the market and existing brewers expand their regional distribution. Meanwhile, CEO Martin Roper outlined plans to continue investing in the company's brand to sustain market share, while at the same time evaluating spending to ensure investments are carefully allocated to support growth.

Nonetheless, Citi's Wendy Nicholson initiated coverage on Boston Beer today with a "sell" rating and price target of $186, saying, "While craft beer continues to outpace the overall U.S. beer category, the increasing fragmentation of the category has led to slower growth for the more well-entrenched players like [Boston Beer]."

In addition, Boston Beer received a downgrade to "underperform" from "outperform," and a $200 price target from CSLA's Caroline Levy, who noted "ongoing weakness in its flagship brews" and recent discussions with distributors have caused her to reduce her outlook for depletions -- a key measure for how quickly Boston Beer's products travel from warehouses to consumer outlets -- to be flat in 2016, compared to Boston Beer's guidance for depletions growth in the mid-single-digit range.

Now what: Apart from the flat depletions growth expected by CSLA, these analyst notes don't offer any groundbreaking news or change what we already knew from Boston Beer's quarterly report last month. And to be fair, today's drop effectively brought Boston Beer stock back to where it stood immediately following that report, and shares now trade below each of the respective price targets set by the analysts in their respective notes. As a result, for long-term investors willing to watch Boston Beer's growth story continue to play out, I don't think today's plunge should be of great concern.