See this comment by Gregory Maxwell (a core Bitcoin developer): https://news.ycombinator.com/item?id=25007874 https://news.ycombinator.com/item?id=25007874 Say

See this comment by Gregory Maxwell (a core Bitcoin developer): https://news.ycombinator.com/item?id=25007874 https://news.ycombinator.com/item?id=25007874 Saying that PoS offers zero security seems a bit extreme but there's definitely a trade-off.