If you had invested about $74 every month in the S&P 500 for 20 years

This hypothetical investment journey, starting in January 2006, was not smooth. Less than two years in, the global financial crisis arrived.

Along with the Lehman Brothers bankruptcy in September 2008, the S&P 500 was already falling, and it recorded -56.8% down to its low in March 2009. The account of someone investing about $74 every month once fell below half of the invested principal.

But what if you had kept investing even through this crash? The shares bought cheaply in 2008–2009 became the springboard for the big bull market of the 2010s. After recovering the principal in 2013, the S&P 500 entered a historic upswing.

You also lived through the March 2020 COVID crash (-33.9%), but this time it recovered in just 5 months. By the end of 2021, it was setting new highs one after another.

An investment started 20 years ago has an estimated value of about $95k (pre-tax) as of 2026 — 5.3 times the roughly $18k invested in total.

The key to this result is "consistency." Everyone knows it is good to buy stocks at a financial-crisis low (March 2009). But continuing to invest at that moment is psychologically extremely hard.

The advantage of recurring monthly investing is that you do not have to agonize over the timing. It automatically buys more shares when prices are low and fewer when they are high. This "dollar cost averaging" worked effectively over the long run.

However, this result is an estimate. Reflecting FX movements, fees, and taxes changes the actual amount received. In particular, accounting for the overseas-ETF capital-gains tax (22% after a deduction) makes the after-tax amount lower than this.