Thanks! I am sorry but then I do not understand where do the NBBO contained in OPRA come from... I am sorry for the (surely) naive...
Who is the designated primary market maker for the SPX? Is there more than one? Which of the e-DPMS provide liquidity services on the SPX?...
Is there only one designated primary market maker on the CBOE SPX? Who is it? Which of the electronic designated market makers are active in...
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