I only think about the percentage loss (and invest money I can afford to lose), and then buy and hold more often than not. From my "fun" portfolio personally,

I only think about the percentage loss (and invest money I can afford to lose), and then buy and hold more often than not. From my "fun" portfolio personally, which is mostly tech stocks, there are many small losers but a few massive winners that outweigh the losses. When I was trading on a daily / weekly basis I never saw this, but after holding for quarters it's become my new approach. Instead of checking daily, now I check the numbers every few weeks. If it's any consolation, I got started with investing in the 3 months before the housing crisis in 2008 and watched 50% of what I invested in relatively stable funds disappear basically instantly. That was depressing but in time all of them came back. For longterm, you've really gotta trust dollar-cost averaging and just waiting out the bumps. After surviving that rough introduction, everything else feels minor.