Well, I'm not an expert of market structure and all his mechanics like Eric.
Only my own speculation but I think it gonna have the same effect as computers when U increase their bandwith: that's the equivalent of accelerating time.
I don't think the timming of this implementation is coincidence as well as IEX becoming an exchange few days ago. Maybe liquidity will become more easily accessible to big participants (fed?). That would make markets look more nervous to us (in fact it's the same thing as before but even faster) And so they will be able to manipulate them better (because if markets are manipulated wich I believe they are, that means it becomes "heavier" and "heavier" through time)
As I'm expecting a crash (purge) in the markets that could be one of the big catalysts. But you have to understand what I consider a purge: that's when liquidity is not present enough to allow some leveraged participants to close their positions before they "explode". Like in a game of musical chair U HAVE TO finish the cycle with some loosers.
So either it already happened in august of 2015 (very improbable for me) either it's comming and will be: 1_the start of a huge collapse in the real value of the stock market (market versus gold, oil, food etc...) the bubble that everybody is talking about 2_A buying opportunity for people than cannot invest in other things than stocks and bonds because I think it gonna happen with the stock market rising in nominal. In the seventies that happened with a market flat in nominal, next time I think inflation will be worse so even a market crashing in value will rise nominally (zimbabwe/weimar/venezuela style)
I'm a big bear but I'm really conviced that the market can't crash 50% or more like in the past and that either we crash and rise for years or just rise for years (nominaly). And I believe a flat market for years is also impossible so it's an on/off market. 9/25/16
Look at the 2002 2006/7 period Markets were rising in nominal but crashing against gold and oil an copper etc... I expect the same kind of things but drived by worst fundamental reasons than the ones that were driving at that time 9/25/16