What happens if you miss the 10 best days on the stock market

arvy's Teaser: 20 years of stock markets. Roughly 5,000 trading days. You miss 10 of them — the best ones. Just 10. Result: your wealth is cut in half. This statistic is the strongest argument against market timing — and the strongest argument for: staying invested, having a savings plan, and understanding what you own.

The Statistic That Changes Everything

Here are the numbers, based on the S&P 500 over the last 20 years. You invest CHF 100,000 at the start and stay invested:

Read that again slowly:

10 days. Out of roughly 5,000 trading days. That's 0.2% of all days. And they make the difference between CHF 320,000 and CHF 150,000. More than half your returns come from 10 days.

Miss 30 days — just 0.6% of all days — and you end up with less than you started with. 20 years invested, risk endured, volatility suffered — and still lost money. Just because you weren't invested on 30 of 5,000 days.

The Best Days Come When You Least Expect Them

Here's the part that destroys market timing once and for all:

This means: the biggest price jumps happen in the middle of the panic. Exactly when everyone is selling, the news is apocalyptic, and you're most afraid.

If you sell during a crisis — to "limit losses" — you'll very likely miss the exact days that save your wealth. You sell at the bottom and miss the recovery. That's the most expensive mistake in investing.

Concrete examples:

24 March 2020: The S&P 500 rises +9.4% in a single day. Two weeks earlier were the worst crash days since 2008. Anyone who panic-sold missed this day.

13 October 2008: +11.6% in one day. In the middle of the greatest financial crisis of our generation. The headlines: "The financial system is collapsing." And yet: +11.6%.

13 November 2008: Another +6.9%. One month after the worst crash. Anyone who stayed invested captured both days.

"You can't plan for the best days. But you can be there — by simply staying invested."

What This Means for Market Timing

Market timing — trying to sell before the crash and re-enter afterwards — fails almost every time. And here's the mathematical proof:

To time successfully, you need to be right twice: once on the exit and once on the re-entry. The exit — maybe. Some sense when things are getting dicey. But the re-entry? Almost nobody re-enters at the bottom. Because at the bottom, fear is at its peak.

What actually happens:

The Solution: Stay Invested + Savings Plan + Understanding

If market timing doesn't work, what does? Three things:

1. Stay invested — always

The simplest and most powerful rule. Don't sell in a crisis. Don't "step out for a bit." Stay invested. Anyone who's present for all days automatically captures all the good ones.

2. Have a savings plan

The savings plan is the ultimate anti-timing mechanism. It invests automatically — even during crises. Especially during crises. When prices have fallen, your savings plan buys more units. Without you having to make a single decision. (→ The Power of the Savings Plan)

3. Understand what you own

And this is the arvy difference: when you know why Nestlé, Visa, or Microsoft are in your portfolio, you have conviction during a crisis that goes beyond "the market will probably recover." You know: these companies have survived crises, paid dividends, and gained market share — in every recession of the past 50 years.

That's the difference between "I hope it gets better" and "I know what I own, and I trust it." The first leads to selling. The second leads to holding.

The One Question You Should Ask Yourself

Not: "When is the best time to enter?"
Not: "Should I buy now or wait?"
Not: "Is there another crash coming?"

But: "Am I invested — and will I still be in 10 years?"

If the answer is yes, you don't need to worry about the 10 best days. You'll capture every single one of them.

"The biggest risk in the stock market isn't the crash. It's not being invested during the crash."