As I mentioned here and here, a drop and hold below the 150 Bull/Bear line-in-the-sand level would see a retest of the June 27th lows. You can see from the 60-Day 60-Minute ratio chart below, price closed today at 121.5. There are two remaining gaps below that level yet to be filled, which, when filled, would realize that retest.
Each candle on the following ratio chart depicts One Year. You can see clearly that today's close sits just above the 116.61 open of the 2007 candle.
Each candle on the following ratio chart depicts One-Quarter of One Year. As of today's closing level, upward Momentum is lower now than it was at the open of the Q1 2007 candle...hinting that the buying and bullishness seen on the SPX this year (which pushed Momentum to an all-time parabolic level on the Monthly ratio chart), is, in fact, weak, unsustainable, and without serious merit.
CONCLUSIONS:
Volatility has now risen sharply, after a summer of complacency. Look for wild swings in both directions on these ratio charts as long as price remains below 150. And, if it drops below 80.00, after a retest of the June 27th lows, I'd say that equity markets are in serious trouble and in for a substantial drop.