3rd leg.
Over 40% of the SPX cash will be wiped off the market next week (JPM will lose a heck ton of $). Some will be written off the markets liquidity, some will be repositioned (common sense suggest lower).
SPY is equity settled and will have a LOT of pressure next week.
The 3900 support was half sold already on fridays closing, that will be easly broken.
Until August espect 3900-3600, probaby between upper side mostly, while pop-ups above 3900 seem scarse, but even then 4000 looks unbrakable.
Enjoy