IMO, the gaps are caused by a sort of periodic dumping of shares:
Big sellers are ruthless for a min or 2 selling, even at the bid they are dumping as we see. This removes all the buyers so quickly that it is irrational to keep selling. ... then they pause for a few minutes and then resume this pattern. If they are the only ones selling at the bid and drive it down 2 cents and then take their hand off the trigger, the result is a gap between bid and ask.
Watching this today made it almost seem very sneaky the way the selling happened. It was periodic / made buyers watch and then enter to only watch it drop again. Everyone is looking for the bottom and these sellers are hoping to attract more buyers while dumping by making (bottom looking) prices... drops... levels off, pops a bit, drops even more... levels off, pops a bit... drops even more... on and on
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