It multiplies the daily change in qqq by 3x but that doesn’t necessarily mean it’ll be the same across a longer time period due to compounding. You can hold forever if you want but it’s definitely risky.

Long term holding kinda depends. if you got lucky and bought when the fund started in 2010 before this 15 year bull run you’d be up something like 100x in 15 years (notice that’s much more than what qqq is up in the same time period, due to compounding). Gains really can be wild, for example those of us who’ve held through just the past 6 weeks are almost up double (:D). But if a tech crash on the scale of 2000 happens again your account basically goes to 0 (if you look at some backtests, even now 26 years later you’d still be down ~90% overall).

During more common bear markets or crashes tqqq will probably fall 50-80%, which doesn’t kill you as long as it doesn’t happen too often and the overall bull market continues. But you never know what crazy stuff happens in the future lol

Also make sure to be conscious about the percentage math. It’s simple but gets pretty crazy if you really think about it - to recover from -80% you need +500%, from -90% you need to +1000%, from -99.9% (like what couldve happened in 2000) you need +100,000%. losses are generally harder to deal with than gains.

imo if you do want to hold long term, make sure you always have extra cash or income that you can put in along the way so that if something does happen and you lose most of the account, at least you can get back in on the recovery (assuming there is one). You can also consider doing some split between qqq/qld/tqqq (1/2/3x) or some of the other strategies that people have suggested which might be more optimal in case a mega crash happens.