The ProShares UltraPro Short QQQ ETF (SQQQ) closed down 2.16% at $28.93 on December 13, as the Nasdaq 100 Index (NDX) rose 0.76% to 21,780.25, driven by bullish sentiment and a new 52-week high. The Nasdaq 100's upward momentum was fueled by increased net buying of index products, as highlighted in the latest CFTC Commitments of Traders report, which showed a rise in long positions by 6,000 contracts. This optimism was further supported by reduced demand for volatility protection, evidenced by increased short positions in the VIX. The potential inclusion of stocks like Palantir and MicroStrategy into the Nasdaq 100 as part of the annual rebalancing also contributed to the positive sentiment, as mutual funds and ETFs tracking the index adjusted their holdings. Additionally, the broader market's anticipation of a "Santa Claus rally" and the absence of significant economic announcements bolstered risk appetite, with the Nasdaq Composite gaining 0.1% to close at 19,926.72.