In any single year, the stock market could be up 30% or down 20% — there's no way to know in advance. But stretched out over 10, 15, or 20 years, those wild individual years tend to average out into something much closer to the market's long-term historical trend. Time doesn't remove risk entirely, but it gives a rough year the chance to be balanced out by the years around it.
Someone who happened to invest right before a historically bad year — like 2008's global financial crisis — would have watched their portfolio drop sharply and felt like it was a disaster in the moment. But someone who stayed invested continuously through the years that followed would have seen the market not just recover, but go on to multiply several times over across the next decade and beyond. The single worst year on record became a barely visible dip on a 15-year chart — but only for the person who didn't sell partway through it.
A long-term growth approach isn't about avoiding bad years — they will happen. It's a trade: accepting real short-term ups and downs, in exchange for the strongest realistic long-term outcome of the three approaches. It only works if the timeline is actually long enough to let that trade play out.
With 10 or more years on the clock, time does most of the heavy lifting — staying invested and consistent matters far more than trying to guess the market's next move.