28 BTC moved through the bay market and the price remained pretty much the same. Too bad the history isn't longer or the block explorer doesn't have greater search capability.
Laundering? Payoff? Normal altcoin market transactions?
Possibly somebody selling to themselves to generate volume as an attempt in making Bitbay more visible in the volume league tables.
If you can't get value, volume's the next best thing.
Bitbay has actually dropped off the marketcap radar of top 100 coins. It's down at 102 now below Ocupy. That may have prompted the action. (Although the volume's not showing up yet).