Beyond Meat slumped as much as 9.4% in Wednesday trading after an analyst downgraded the stock, citing fading growth potential in the US.The tumble is Beyond Meat's worst since October 29.Bernstein analyst Alexia Howard downgraded the stock to "market-perform" from "outperform" while maintaining a $106-per-share price target.The company could improve its growth prospects by expanding its partnership with McDonald's or pushing into international markets, Howard wrote in the Wednesday note.Watch Beyond Meat trade live here.Beyond Meat tanked as much as 9.4% Wednesday after an analyst downgraded the stock on concerns of fading growth opportunity in the US.The plant-based-meat company's sales growth potential could be "largely priced in at this point," Bernstein analyst Alexia Howard wrote in a Wednesday note. The research firm cited a "less attractive" risk-return situation for the stock following an early January rally, and noted its "blue-sky scenario" includes an expanded US partnership with McDonald's.The firm downgraded Beyond Meat to "market-perform" from "outperform" Wednesday. Bernstein maintained its target price of $106 per share, implying a 9% downside from Tuesday's closing price of $117.05.The Wednesday stumble marks the worst decline in Beyond Meat stock since October 29, when it fell more than 20%. The stock initially soared following its May initial public offering, but the expiration of its post-IPO lockup and concern around competition from Impossible Foods pulled shares lower through the second half of 2019.The company could also woo investors by expanding its footprint outside the US, Howard wrote. Growth abroad would significantly boost the company's available customer base and take attention away from looming competition in the US."We believe that BYND has significant growth potential in Europe, which could more than double its [total addressable market]," the analyst wrote, adding a move to China could "take advantage of the protein supply shortage led by the African Swine Fever."Beyond Meat is just days off its best week since July, soaring 27% from January 6 to January 10. The stock soared following a January 7 Reuters report that Impossible Foods was ditching attempts to land a deal with McDonald's. Impossible Foods later disputed the report.Beyond Meat jumped even higher on January 8 after McDonald's said it would expand tests of its PLT burger in Canada. The item stands for "plant, lettuce, and tomato" and uses a Beyond Meat patty.Beyond Meat traded at $108.82 per share as of 2:25 p.m. ET Wednesday, up roughly 47% year-to-date.The company has three "buy" ratings, 10 "hold" ratings, and four "sell" ratings from analysts, with a consensus price target of $100.45, according to Bloomberg data.Now read more markets coverage from Markets Insider and Business Insider:Bitcoin is on its best start-of-year streak since 2012Treasury Secretary Mnuchin says a 'phase 2' US-China trade deal will reverse more tariffsAmazon is launching a new marketplace in the Netherlands after seeing mixed results in its international businessJoin the conversation about this storyNOW WATCH: A big-money investor in juggernauts like Facebook and Netflix breaks down the '3rd wave' firms that are leading the next round of tech disruption Click here to read full news..