I watch tick by tick and tape data when I trade. Those spikes I saw were real trades with registered shares. Often there were very rapid ran up and ran down as if someone was trying to take down someone else's stops. I have no idea if they were real or fake/error trades. But how could they fake a trade or have an error?
I'm not sure how it works, but it happens. Look at a 1 min chart of QQQ this morning at 8:11. A $3.75 move down in one minute with no volume spike? There are definitely real volume spikes happening, but these bad data prints are driving me nuts.
%% SOME errors are easy to spot; QQQ, 2 charts feeds have different close prices @ hour I tend to believe the smaller one, so if larger one is right ,OH happy day .IF not= OK anyway. QQQ has never been as orderly as SPY. On a wide bid\ask like FNGU, spike city on most any time frame + even worse
I saw the spikes on the tick stream, this isn't that unusual as active tickers do have quite a few bad ticks (~5-10 per week) but most a subsequently corrected by the exchange using an error correction tick flag so the aggregators can disregard the bad tick. These were not corrected, although I suspect they are bad ticks that were not caught but the exchanges error correction algo
They weren't corrected on that chart. On my TradeStation they never appeared to begin with. Trades never happened. Why would anyone think (jittery up and down multiple times) they did to begin with is ....
%% Much more commonon Fed days or OCT; in some case its the data feed,[error] especially OCT, especially QQQ or TQQQ, in OCT. In the case of the data feed a big Trender like TQQQ will vary a lot in a part of a second, so an error may not really be an error. Bank clocks in town vary by 5 minutes, another error