The OCC is reporting a drop in on exchange trading in options on the US markets. At the same time OTC volumes are up! This is certainly strange in view of the increased emphasis on counterparty risk.
However, it looks like other factors are at play. High exchange fees, ease of execution and fear of being picked of by HFT seem to be the main drivers behind the shift in volume. Some arguments do make sense. Having your order executed in 20 tiny exchange trade is not always that convenient.
CBOE seems to be in the centre of the discussion as the have a monopoly on some of the listed derivatives.