Tonight, we got a -5 reading on the VO. Let's review a few recent tops to see if this tells us anything.
November 5, 2010 Top
The VO turned negative on October 19 and stayed negative through November 2 (11 straight trading days at 0 or below) before turning positive on November 3-5.
August 9, 2010 Top
The VO never went negative before the downtrend started.
April 26, 2010 Top
The VO had 4 random negative days between March 19-31 before turning solidly negative on April 16-26 (seven trading days).
January 19, 2010 Top
Had one negative VO day as warning (January 15).
June 12, 2009 Top
The VO turned solidly negative on June 3 and stayed negative through June 12 (8 trading days).
Conclusion
Unfortunately, the VO by itself turning negative for one day is not particularly predictive. If it stays negative for a few days, we should probably be on the lookout for other evidence of a topping process over the next week or two.