TradeAlert · 16 mins · $10B notional is big, even for $SPX. Largest trade in SPX this month was executed this morning as a buyer paid $2.60 for 35K Oct 18th (PM expiry) 2700 puts at 11:30ET, as Dec futures traded $2984.50. Premium exceeds $9M and the block opens a three week position that is currently struck 8.6% below spot, with notional value near $10.5 billion. Heading into the close with futures nearly $25 below the buyer's entry point, these contracts are trading near $4.85 - a gain of 86%, just under $8M in 4 hours.