I know their has been some interesing discussions in the past about pairs trading. A lot of this has been aimed at swing trading where the pairs end tracking each other on a day by day basis. I am looking for some pairs that track each other closely on a minute-by-minute basis (even if they gradually separate on a daily basis). The closest pair I have seen so far is LLTC-MXIM (this pair came from previous thread). If some of you are familiar with other pairs or threesomes that track each other intra-day, I would greatly appreciate some suggestions. Thanks in advance.