it's definitely automated programs.
You'll see it on both sides; 3000 bid on island, then later 3000 on the offer.
It's just a market-maker playing a spread game, and since it usually spooks small traders, it usually works for them.
Has anyone had any success trading thin Nasdaq stocks (volume less than 100K)?
I'm looking for new tactics and wondering if there was any money to be made there. Or do the market makers have their way with daytraders...