when boarding aeroplane,
first class passengers board first, follow by business class and then economy class passengers.
When stocks move (since mid Feb 2020),
first tier / blue chip stocks move first, follow by 2nd tier stocks and then penny stocks and half dead / undead / almost died stocks.
anyway, lately day traders should be happy trading those penny stocks.
look at DUO. time to buy was 9 Jun. but the opportunity to buy only last for few minutes.