They usually happen when no one really cares anymore. Meanwhile, we should see tradable action in both directions as volatility reigns. Long-term plays are out of the question right now. Short-term plays, small amounts of capital, defined profit targets and especially exit points are paramount these days and into the future from here. Ratio listed is percentage of calls to puts or puts to calls respectively.
Support is factored from dividing puts by calls at strike levels beneath index closing price.
Resistance is factored from dividing calls by puts at strike levels above current closing price. Small specs are the general trading public with commercials being financial institutions. Commercials are historically on the correct side of future trend changes while small specs are not. Extreme divergence between each signals a possible market turn in favor of the commercial trader's direction.