Because that’s how most wealth is created.

Most investors hold their investments for only six months. Every time you make a decision, you introduce the chance of being wrong—wrong on timing, wrong on price, or wrong on the investment itself. Over time, that decision churn leads the average investor to underperform the S&P 500 by about 5% per year.
For most people, the simplest buy-and-hold strategy is just holding the S&P 500. But traditional portfolios that include bonds typically underperform the S&P by seven percentage points per year.

Designing your own buy-and-hold strategy isn’t easy—but it is possible.
The Stars Model holds just two ETFs—SPY and TQQQ—all the time. Over the past 26 years, Stars has outperformed the S&P by a factor of 17.
After a few years, Stars has an accuracy rate of nearly 100% and virtually zero real risk because of the compounding returns. The ETFs themselves do the stock picking and constantly improve their holdings; your only job is to rebalance annually to keep TQQQ at the desired concentration.

A disciplined strategy beats a reactive one—every time.