Timing when you should be in them is no easier than picking individual stocks. I do not want to hold them for 25 years. The U.S. has more billion dollar companies than any other country. With international stocks you have currency risk which is just another decision that has to be considered.

I worked for two companies that had international exposure. There were often risks that were overlooked. These two companies were not as informed as the foreign company. Investments were made at elevated prices that made performance difficult.

Buy and hold strategies have a limited number of investment options that work. Berkshire Hathaway made value investing work for decades but now is struggling. There are few stocks, funds, sector funds, or international investments that are worthy of holding 25 years.

Stars holds SPY and TQQQ and will do so forever unless they change how they pick stocks. They are both cap weighted ETFs. Their holdings are heavily weighted to the best long term performing stocks. Over time their holdings change. TQQQ changes what it holds faster than SPY.

I believe SPY and TQQQ are the two best ETFs to hold because they produce returns that are twice the S&P when backtested over 25 years. I do not know of any investments that can match that.