Any attempt to artificially depress the price will make it undervalued compared to NDX, thus bringing in the bargain hunters
I don't think that's correct. QQQ is called a tracking stock, that's true, but in reality it's an exchange traded mutual fund. When you buy $100 Million worth of QQQ, you are actually buying a proportionally weighted basket of all the stocks in the NDX. This changes the inherent value of each of those stocks, which in turn changes the inherent value of the NDX, which in turn changes the inherent value of QQQ.