One stock up 370% this year could be hitting a wall

Roku has still has a long-term up trend, says strategist

One streaming stock is blowing the rest away this year.

Roku has exploded 370% since the beginning of the year, far better than the streaming stocks often grouped with it, including Netflix, Disney and Amazon.

Its shares crept higher again on Tuesday a day after plummeting 15%. The stock came under pressure on Monday after Morgan Stanley downgraded to underweight on valuation concerns.

Mark Tepper, president of Strategic Wealth Partners, also sees valuations taking the stock down a peg.

"It's crazy expensive right now ... This thing's priced for perfection," Tepper said on CNBC's "Trading Nation" on Monday. "At this point, more could go wrong than right at these price levels right now," said Tepper. "This valuation looks like they're the only game in town, and they're not. In fact they're actually facing more and more competition."

Tepper notes that its enterprise value to sales ratio has averaged roughly seven over the last two years. It now trades at 11.5 times.

Katie Stockton, founder of Fairlead Strategies, says the stock could see near-term pain until the long-term trend reasserts itself.

"It's a long-term uptrend for the stock. When you see a gap down like this, it's always difficult to determine what to do," Stockton said during the same segment. "When you do see a gap down following a nice up move like we've seen in Roku, it tends to mark the beginning of a pullback ... but the impact even of this dramatic gap really is just short to intermediate term for the stock."

"It's not impacting the long-term uptrend which you can really judge by the rising 200-day moving average. There is some support between here and there, right around $117 to begin with," said Stockton.

Roku would need to fall 18% before reaching $117. It last traded at that level in early November.