You are correct Vertical1 - things that have a deep market ( lots of buyers) and can be converted into cash quickly at or near their prevailing value...
No such thing as a free lunch. No fee perhaps, but I'll bet in the fine print your shares are being lent out to cover options. They are making money...
I am weary or is it wary, or both, of the fact that all of the sh1tcoins are running up like fireworks as well. The 'space' would be more believable...