RE: purchase3 May 2017 15:08
I believe the "actual spread" is different to the "published spread" (which is less volatile). When MMs offer buys at less than the midpoint it shows as a sell, and can give the impression of a massive sell-off, which can become self-fulfilling.
it is scandalous that the actual buy or sell flag is not shown, but is left to be calculated on a whimsical basis- so subject to manipulation. Only the PI's lose money, MM's make money on the rise or fall, so they are laughing all the way to the wine bar.