Small changes in the put/call ratio are considered unimportant, whereas extreme changes convey information. Two rules of thumb are that a ratio greater than based on a 10-day moving average would be excessively bearish and thus a buy signal, and a ratio of less than would be excessively bullish, and therefore a sell signal. 1) 0.70,0.65 2) 0.80,0.45 3) 0.90,0.25 4) 0.95,0.05