This is a quad witch option expiry week. The futures front month is rolling over but we have not yet made the change to September futures.
Volumes remain remarkably light even for June.
Support is obvious.
Keep a close eye on the VIX volatility.

"The Fed already buys and sells foreign exchange to prevent disorderly conditions in foreign exchange markets. The Fed has assumed a similar responsibility in the market for government securities. The Fed could support the stock market directly by buying market averages in the futures market, thus stabilizing the market as a whole. The stock market is certainly not too big for the Fed to handle." Robert Heller, Federal Reserve governor, WSJ, Oct 27, 1989