I have not found a stock that "always" presage the market direction, the Q does quite a lot (and in the Q QLGC and MERQ lead that pack often, but not always). Used to be that IDPH would lead the pack of the bio/pharma exclude big pharma), BIIB, I am not sure yet, it does not have the same volatility IDPH used to have. I think that GILD might be a new "canary">". As for tension, I usually use an Island screen with depth of about 15 bids and asks and you can see the tension change minutes before the market changes in some of these issues.
As for superconducting synapses, no, not involved with that and am not sure why it would be useful either. I have a "plateful" of "strange" applications for ambient superconductors, but that is another story.
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