Bitcoin is gambling unless you hold for at least 2 years, 3 years is almost a sure thing

I ran the numbers using all the close-prices for all days since the end of 2014. I calculated the fraction of days you could have bought bitcoin on and lost money on that bitcoin if you sold on the worst possible day in the future after holding for a period of time. Here are the results:

Holding for at least:

6 months: 45.82%
1 year: 36%
2 years: 24%
3 years: 1.66%
4 years: 0.74%

So what that means is only 1.66% of people who have held for 3 or more years could have even possibly lost money if they made the absolute worst paper-hands selling decision. If that's not as close as it gets to a sure thing, I don't know what is.

On the flip side I also calculated what fraction of people would have lost money if they held for a certain period of time, and then at that point realized they needed to sell and had a 30-day window to choose a favorable day to sell. Here are the results:

6 months: 28.37%
1 year: 22%
2 years: 18%
3 years: 0.21%
4 years: 0%

What this means is that even if you chose the most favorable day to sell out of the next month, 18% of people who held for 2 years would still lose money. Not terrible, but no sure thing. But if you hold for 3 years, less than 1% of people will manage to lose money. And there were no days whatsoever where holding for 4 years resulted in a loss if you sold 4 years later.

Here's the spreadsheet: https://file.io/Cru9TmbP3WT6