Roku Inc. shares /zigman2/quotes/205087179/lastsale ROKU +0.01% are off 2.2% in premarket trading Tuesday after the company disclosed that selling stockholders would be reselling up to 571,459 shares due to an agreement reached when Roku announced its plans to acquire advertising-tech company Dataxu. That deal closed on Nov. 8. The selling stockholders listed in Roku's Monday afternoon filing are investment funds affiliated with Thomvest Ventures, offering Class A 150,281 shares, funds affiliated with Menlo Ventures, offering 130,107 shares, and funds affiliated with Flybridge Capital, offering 62,473 shares. Sky Ventures Limited will offer 94,398 shares, Atlas Venture Fund VIII will offer 57,707 shares, and other selling stockholders will offer 76,493 shares. Roku's stock has risen 423% so far this year as the S&P 500 /zigman2/quotes/210599714/realtime SPX +3.41% has increased 25%.