[nairboon]

> XRT only holds 0.71% GME shares, so seems like an extremely inefficient way of shorting it.

No, actually it's quite efficient. You short XRT and simultaneously go long all other components except GME. Now you are net short GME without having to report a short position on it or borrow shares in the first place.

[auntienomen]

Except that you need to buy a _lot_ of stocks to cancel out the non-GME positions. It's probably 100x more expensive to short Game Stop this way. Not economically feasible, even if you could find a broker willing to do it.