in daytrading you have limit loss and daytraders risk like $1000 that is it. and prices don't change much during trading hours.
it's over the weekend or overnight that 'news' can crash the price like 50% overnight for stocks that blows up accounts.
that is the reason daytraders don't hold overnight, they are traders and can open a position next day
daytraders penny cheap in commissions. way cheaper than retail commissions.
in futures,,it's max 5% the market will go up or down it's called limit down..it's not normal for prices to crash 5% in day. the exchange would put a lock limit on the instrument. stocks and penny stock,,there is no lock limit. it can drop 90% or 95% overnight. or increase 500% overnight..stocks are like options where as commodities index futures are more stable prices and don't change much on a daily basis.
a 5% change in stock is minimum,,but if the 'market' crashes 5% it's considered a 'catoshproe or 'CRASH'