Why there's only one ETF and one MF for NDX100?

SP500 has so many different ETFs and MFs to track, and the ER is very low.

But for NDX100, only QQQ and USNQX, and the ER is fairly high (0.2x%, 0.4x%).

Given that tech stocks are so hot now, why there's no more choice?

 

TQQQ, SQQQ, QLD, PSQ, QID, QQX, QQE, QQXT, QQQE

 

%%
That;
+ related,XLK,TECS,FTEC,QLD, FDN,semi liquid EBIZ
QQXT is a strange one ,no tech/LOL

 

Those 2/3X and any short ETFs has systematic flaws by design. So I don't think they are qualified as ETFs. I think they are implemented as ETN?

 

There are ETFs highly-correlated with QQQ. Most of them have a lower expense ratio.