Underestimating the down strength

I always underestimate the strength for a particular move. It's never perfect for me in managing my trades. I'm currently having a light position to the downside. How low will it go before a rebound? I think that this next downside move will not be so strong as compared with the one in early October. The ratings for various sectors remains:

USA	Longterm	Midterm	Shorterm
S&P500	Down	Down	Down
DJI	Down	Down	Down
Nasdaq Comp	Down	Down	Down
AMEX Natural Gas	Down	Down	Down
AMEX Oil	Down	Down	Down
AMEX Security Broker	Down	Down	Down
KBW Bank	Down	Down	Down
KBW Insurance	Down	Down	Down
PHLX Housing	Down	Down	Down
PHLX Shipping	Down	Down	Down
Sig Steel	Down	Down	Down
S&P Retail	Down	Down	Down
AMEX Biotech	Down	Down	Down
AMEX Airline	Down	Down	Neutral