The entire premise behind buy-and-hold investing is that you expect your investments to grow by ~7-11% per year, over the long run. If you're expecting your inv

The entire premise behind buy-and-hold investing is that you expect your investments to grow by ~7-11% per year, over the long run. If you're expecting your investments to stay flat over the long run, there's no reason to invest in the first place. Given that you expect some growth every year on average, it makes sense to take into account the opportunity-costs of delaying your investments. Or to put it in more obvious terms: Investing $18k today, is better than investing $18.2k in 2019, which is better than investing $20k in 2028.