TECL mostly, and a little less than half that amount in TQQQ. I just look to make sure they trade enough shares to ensure liquidity and low fees. The fees for 3x funds hover around 1% and that's a given.
There's a few differences between the two but the big, obvious one is that one is Tech and the other is Nasdaq 100 (predominantly tech, but not all tech.)
As for your decision, repeating what i said before, i like to build the position over time, let winners ride, and never double down. As for tech in particular, i have been thinking about your question from a few days ago and my belief is that there is substantial upside still. Watch the pull backs. There just aren't many: Significant.
And those that do happen, quickly find a recent level they traded, quickly solidify, and rebound fast from there. My take away is that everyone and their brother wishes they were in it, are buying it up however reluctantly, and are having wet dreams over finding a good entry point somewhere lower. Pent up demand will keep this sailing.
Of course, there's always some risk,
Good luck to you, but i believe the answer to your question is right under our noses. Hiding in plain sight. And i would just have a good exit strategy thought out and ready to implement should you need it.