%% POST market, premarket, +biotech stocks\ETFs spike all the time; in those cases its not bad data. Same thing as a forced sale\foreclosure\panic in semi liquid REALTY. [FNGU trades all the time with real spikes-LOL, not a stock of ETF tip] Another hint is a liquidity leader like SPY with wide bid\ask. Yes, intraday fake spikes happen, but if you have lot of data on SPY...., can usually see error . $5 one minute spikes in TSLA look fake, because the other 2 charts dont show those spikes.
Is it possible that those "bad trade" spikes contain useful information that is discarded when the spikes are "corrected?" .
%% LOL even a stopped clock is right 2x per day Strange , ever noticed how many MAGAzine clock or watch ads have the watch stopped @ 10;10 am or pm?? Same with internet watch ads today. Most anything is possible, but i use clocks + calendars more , dont own a wristwatch anymore.
Yes, I've noticed and it's a pain in the ass. I use TOS for charting, so I can just right click on the bar and correct it. But it seems like I'm doing that every 10 minutes or so lately. Also my mean reversion back testing has been completely worthless. I've always verified back testing results, and more that half of the winning trades have been from bad ticks over the last week.
%% Sure did, on bigger clock + calendar; not on a wrist watch. Fake print in 2002 QQQ/$30 area bear/ did catch the bottom for that week. But look @ so much data, never weigh fake news or fake anything much. OH well, new NOV month