Why would you bother investing in two stocks that are perfectly inversely correlated. Your return after fees and brokerage would be negative because every % you made in stock A would be countered by your % loss in stock B. Better off putting your money in a term deposit, government bond etc. if you don't want to ride the excitement of the market....
The best I can think of though would be A200 (positively correlated to market) & BEAR (negatively correlated to market). Another example would be AUDS vs. YANK.......