Since September 1st there has been a big divergence of these two stocks the rely heavily on the engineering and construction industry. I am a fan of TRMB and have recently doubled my position. Something is off the mark here and I think a strategy would be to buy TRMB and short CAT. If TRMB falls back to $20, then CAT is heading back to $30. Personally I think you'll see TRMB jump 20% by November 1st, after earnings are announced.