An ordinary joe could just put in a limit order on good blue chips stocks at 20% below current prices. If you had such orders in on Monday morning, you might have managed to buy something at a very cheap price.
There are a lot of happy traders who do just that. Personally I guess I get to fidgety and want results right away so I just stare and wait till the price is met and then I buy. I bot a bunch of etf's today; we'll see....