Ive watched over the years firms like renaissance technologies, getco, wolverine, optiver, citadel, etc....grow into powerful profit generating machines and a true force to be reckoned with, and estimates is the top HFT firms made 21B last year when everyone else was looking into the abyss and over 70% of volume traded on stocks is conducted by these firms. Competition amongst exchanges has helped these firms flourish. Now the media spotlight is on them and social movement could change the rules going forward. My question is; is HFT a bubble? or is it a more fundamental shift into how markets are made? The more traditional on-floor market maker now competes for order flow with these firms and has loss significant business to them. Are these firms better equipped to price markets and provide liquidity than the traditional mm's? Maybe its an evolution towards those with the most sophisticated risk management systems, those with the best hedging capabilities to manage their inventory will win? But then again, we have seen many bubbles in finance over the last 10 years, IPO, CDS, CDO, stat arb, commodities, etc.....many players within those fields blew up. Thoughts?