rough estimate nta 40c 30 june 2009, page-11

it's possible only in theory. You couldn't even do it in hindsight. Try it. look at an interactive chart of any stock for the past 3 years and cover all the the highs and lows to the right except for the first day 3 years ago.
then, on paper, decide when to buy and when to sell revealing only one day at a time. Even with the benefit of knowing how that stock has performed, you won't be able to pick anywhere near 50 10% gains.
i repeat my offer to give anyone half my profit to get me 50, 10% gains in any stock.