What makes stocks like SQQQ go up? Is it a combination of demand but also the ETF formulas holding the stock together?

In traditional stocks, supply and demand dictates when a stock goes up or down. But for stocks like SQQQ that are directly correlated to QQQ performance, what dictates the price? Is it a combination of demand SQQQ but also the ETF formulas that dictate how it will behave vs. QQQ? Or does SQQQ demand have almost no role and rather it's a function of how many people are selling QQQ?