Thank god for that secondary, or else there would be no volume in the market today. No, seriously. Courtesy of the biggest and most botched secondary offering in history (you are welcome overpaid Citi bonus recipients), and thanks to Goldman et al buying up every share that has a $3.1x handle (we'll see how long that continues: after all someone has been loading up on Citi CDS to the gills) Citi accounts for 47% of all NYSE volume. Add the other fins, and the HFT are running straight out of luck. Watch for the cannibalization among the high frequency scalpers to start in earnest very soon.
Here is the ratio of C to total NYSE volume: