Roku shares plunged 13 percent Wednesday following two Wall Street analysts' downgrades.
The stock had a stellar run-up to start 2019. Roku gained nearly 100 percent since December 31, outperforming both Netflix and the broader S&P 500 - which gained 35 percent and 12 percent respectively.
Loop Capital analyst Alan Gould lowered his rating on the stock to Sell from Hold and set a $45 price target.
"The market is looking for growth and Roku exhibits some of the highest unit and revenue growth of any of the high growth internet/media stocks...However, the company faces substantial potential competition and we believe it is difficult to justify the valuation," Gould wrote in a note Wednesday.
Separately, Macquarie Research analyst Tim Nollen cut Roku to a Neutral from Outperform, saying "we believe it is difficult to justify the valuation."
Cerity Partners' Partner and longtime Roku bull Jim Lebenthal liquidated his position on Wednesday. Lebenthal bought shares on January 7th and captured about 72 percent upside with a cost average of $38.50. Roku stock sold for as low as $61.14 Wednesday, 13.5 percent lower than Tuesday's closing price.
While Lebenthal still believes in the company longer-term, he stands by his decision to sell his shares. "It's just too expensive," he said on Wednesday's "Halftime Report". "When this stock goes down, it keeps going down...don't try to catch a falling knife. Wait for this thing to bottom. When it bottoms, we'll talk about getting back in."