Semantics, for every buy there has to be a sell. Fidelity shows that transaction as green indicating a buy and the only way that can happen is a "good until cancelled" order where someone put in a large buy order and had some of it filled at the bid. Still a buy although the charts can be manipulated by the MM's.
I have done that before, put in bid support and when the order filled it showed up as a buy. Doubt that it makes a lot of difference however in the long run.
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