Quote from total_keops:
C is known as THE high frequency stock for automatef HFT market making. You are competing with the big boys. Their orders are out way b4 you saw you had to so you are always the sucker in this game IMO.
Your other idea is also a good one but it is know as correlation trading in the HFT world. If PEP move 3 cents then you can assume KO will move at least 2 so you hit and provide 2 cents away. For achieving that you will need some serious ammo to beat the algos.
As far as C, you can't be first in queue on the major ECNs, but there's still plenty of room to trade it... I've had no more than a handful of negative days in C this whole year.
As far as KO/PEP, his BP won't even let him take 100 shares of both of them, AND while yes, he can maintain some neutrality being long KO and short pep, their strong correlation to the S&Ps will mess him up. Also he's limited to a 3 cent stop - pure noise.