SNXX is trading 3.99% lower at $15.74 as chip stocks pull back after a sharp rally. - Sandisk was down 0.92% in premarket trading, with several other major chip names also lower; Nvidia was an exception. - The broader semiconductor ETF had risen for five straight sessions, while major U.S. indexes were higher. - No new Sandisk announcement was identified as a catalyst for SNXX, the 2× daily Sandisk ETF; evidence points to sector pullback and profit-taking.