DTCC reported option data shows a very big GBP/USD option trade flow

28 Dec expiry, 1.2500 GBP put/USD call, trades more than GBP 500-million

Implied volatility would have been low-mid 12's - premium around 18 GBP pips

Looks to have been a buying interest - potentially hedging no deal Brexit

Market optimistic, but time is running out, no deal remains tail risk

Option risk reversals retain a high premium for GBP puts versus calls

Benchmark 1-month risk reversals regain 0.9 from 0.7 - taking no chances

Even with a deal - GBP's upside appears limited nL1N2I50L7