I bought and sold more than 100k shares today. I never held more than 5k shares.
I managed to get in the early run for a 30% gain. The rest of tge day I was flipping 2% trades. At one point I bought 5k shares and sold it for a 3% gain in less than 20 seconds. Then put my limit buy in, had it triggered and sold for 2% gain before I could even set my stop. Im sure there were thousands more like me trading the ultra short term technical patterns and bounces.