Something is building in BTC's end-of-month expiry. July 31 expiry shows $7.7B of call open interest against $2.8B of puts. $1.79B sits at the 70k strike and $1.38B at 72k. Those two strikes hold 41% of the expiry's call OI. $665M of the 70k calls and $680M of the 72k traded today alone, which are likely call spreads. Someone could be taking advantage of cheap potential upside with volatility close to historical lows.(Delphi Digital)