Fragmented markets and the windows of observation

Financial markets are today fragmenting into tens of markets world wide. It opened a way for arbitraging prices between them. Regulation both in Us and Europe are working hardly for synchronizing market with regNMS for Us and Mifid II for Europa but technology is becoming smarter and smarter for detecting patterns and hidden liquidity and the complexity of orders types of exchanges give blackboxes owners frontrunning advantage. Market toxicity is a main concern for institutional investor which target long term. Again given our window of observation we have different metrics that matter. Long term investor care about fondamental like Earning ratios, corporates news and so on for an trader or high frequency trader with microsecond timescale windows of observation it’s all about microstructure, order types, network infrastructure, patterns and impacts. Given your windows of observation you are forced to use a certain kind of strategies. Let me recall you this sentence from my dear teacher Seth Godin « You cannot be seen until you learn how to see ». Know your windows of observation and you will know how to see but the goal is to not be seen by other markets actors. Compromise or Insolvability ?