The activity can be limited: Once in about 5 years, buy a diversified portfolio of 30 companies in at least 10 countries on at least 2 continents in at least 3 unrelated industries, and forget for 5 years. It’s easy nowadays through many banks’ websites. Maybe prefer to buy in a depression and sell on a bubble if you’re feeling extra active.

Between stock sprees, save into a regular savings account.