First, I'm only trying to learn about investing, I'm in high school so I won't be putting money anywhere at least for another year.
I was researching about etfs and looking at a site (justetf) at the performance of many etfs through the years. I saw that if you filter to maximum percentage growth over a year you can find a lot of them with +20% to even +50%, and most of them maintained that for like the past 3 to 5 years.
I'm sure it's not that simple and I still have a lot to learn but why wouldn't someone put money on like 3 of the ones with really high and relatively steady growth (recently) and leave it for like a year and then see. I know you can't predict future based on past performance but with a bit of research on each sector of the market an etf covers couldn't you make an informed decision?