A bit of everything.
1) Some manufacturing numbers were up more than expected.
2) Some feeling that Repub victory in the House will stop or slow down the damage done by Obama and the hard left.
3) There is excess capital looking for ANY good news.
4) The continuing fall or the dollar makes us look good overseas. So, firm like Caterpillar do well if foreign firms buy their equipment at devalued prices.
WARNING: Obama (a monster that is the creation of Dr Frankenstein putting together body and brains from Woodrow Wilson, Herbert Hoover, FDR and Jimmy Carter) is considering a tariff war with China.