Lots of people in the market talk about end-of-market strategies that make small profits regularly but lose it all in one go when a black swan event happens. There are also many discussions about arbitrage between YES + NO, but these are mostly from people who haven’t actually run the strategies themselves. 1. End-of-market strategies can’t just blindly go all-in. With so many events in the market, a proper end-of-market strategy involves diversifying across events. Also, event selection isn’t as simple as jumping in when you see 99%. There’s room for strategy optimization when deciding whether to sweep the end-of-market orders. 2. YES and NO share the same order book. This means that using a double taker strategy makes it impossible to buy YES + NO < 1. Only by combining Maker + taker or Maker + Maker can you potentially buy YES + NO < 1. This is called a market-making strategy and has nothing to do with arbitrage.