When it gets down below $5 they usually do a reverse split to get the price back up to keep it from going to '0'
That's what I've seen anyways. Look at FAZ or FAS chart.
If you have 10 shares worth $5 after they do a reverse 1 for 5 split you have 2 shares worth $25.
That way the price can keep dropping and not go to '0' and the fund can stay alive.
Thats my uneducated guess.