TQQQ is up more than 100x since 2009. What is the optimum amount of leveraged long QQQ? To maximize profits in a bubble, what is the max long one should be? I am sure many S2007S would say 100x. That is not a serious answer because a -1% move will wipe one out.
Doesn't optimum leverage depend on risk tolerance? the lever comes from borrow (margin). How much %debt you are willing to carry drives leverage. For max whichever broker provides highest margin multiple defines max leverage. For retail traders even 50% from margin will be enough to cause ripple.
Somewhat but even if you were infinitely risk tolerant, you still don't want to leverage until a small move will ruin you.
There is no such thing as optimal leverage. Personally I prefer as high leverage as possible perhaps 100X, or better still 1000X or beyond. some traders prefer to have zero leverage ( my goodness ) ! The brokers / Exchanges decide on the amount of leverage. The other question is how many lots should you be trading? You need to refer to your own trade plan which should talk about money management. Some might trade NQ with 2 minis, some 5 minis, some 10, 50 ... Obviously, for beginners, start with small quantity. Then increase it as you become more confident and successful. It seems that your money management is not in place. Go get it done.
Look at daily or even weekly charts and play around with moving averages and see what you are comfortable with. It's early pre-market now as I'm writing this, and as of now qqq is continuing its parabolic move. I wouldn't consider sizable positions at this point.