No responses yet, but if you are curious, I just correlated the BID and ASK to TOS's SPX chart, which implied the BID/ASK data source is used for their SPX charting. Note: relationship of each BID and ASK (mid) to the HIGH/LOW/CLOSE values for each BAR for any time aggregation. Note the widening after market hours also. It seems to all seem valid now, while I still do not know the source, it seems trustworthy for my needs. See chart below and the relationship to the BID ASK data.
