I agree to an extent as if they go up 15-20% consecutively which has happened but yes, you must keep enough cash not to get called. Anyways in the rare times that happens, well short them after those spikes.
Just look at a chart of RIFIN to FAS/FAZ and you will see the decay factor over time...also DRV/DRN--look at all reverse splits since inception,
You can also hedge with options and cash in on those and sell covered calls.
Anyways, look at the SLV 3x leveraged ones now as they ran aggressively. Sam thing will happen to them