While the hammer has not hit on all pieces just yet at Bonham's, Banksy is still killing estimates.
There has been speculation on the sheer quickness that his market increased in the recent year. Though I would have normally agreed with the naysayer's , I can no longer agree. I am sold on the market value of a Banksy piece. From what I can date, Banksy became an international commodity after U.S. Esquire featured him in the genius issue, December 2005. His work was solid in these days prior to the article, just more genuine. And these are the pieces that are doing well because they are the most scarce. The pieces that people bought because they liked them, and there was thought behind them. Not the pieces that you had to buy, because it was Banksy, and there was a buck to be made.