The 225% gain in Bitcoin over the three years to Sept. 23 rests on a tiny set of sessions. In an Oct. 5 note, Grayscale head of research Zach Pandl said that less than 0.5% of trading days had enough upside that excluding them trimmed cumulative return by more than half.But the five best days alone are enough to do the damage. Remove those and Bitcoin still has a 95% gain, well under half of its total 225%.The Nasdaq-100 keeps a 21% profit without its 15 strongest sessionsPandl said the figures were published in Grayscale’s research series The Stack, and used spot BTC/USD prices. Missing ten sessions takes the gain to 27%, and missing 15 drops Bitcoin into an 11% loss.The Nasdaq-100, which tracks large nonfinancial companies listed on Nasdaq, posted a 109% return over the same period. Without the 15 best days, the index was still up 21%, a sign its returns were more evenly distributed.Before the days were taken out, Bitcoin’s 225% return was more than double the 109% return of the Nasdaq-100.After those days go, Bitcoin’s advantage over the index turns around. The coin ends with an 11% loss compared to the Nasdaq-100’s 21% gain.Pandl lays out the result in terms of opportunity cost. For an asset as volatile as Bitcoin, not being in the market is a risk in itself, he wrote, even if risk is usually measured by the chance of losing money.“Investors waiting for volatility to subside or the outlook to become clearer may find that much of the repricing has already occurred,” Pandl wrote.Pandl backs steady exposure over market timingThose sessions can’t be reliably spotted in advance, Grayscale says, so an investor only catches them by already holding the coin. For long-term investors seeking capital gains, its advice is to maintain steady exposure and not to try to time the market.Pandl draws three lessons from the uneven gains. They show how difficult it is to time Bitcoin exposure, the cost of being on the “wrong side” of volatility and the price of giving up long-term upside.Grayscale’s numbers exclude management fees and expenses, and the firm says they are illustrative.Grayscale has seen Bitcoin’s ups and downs all year. A Pandl report in February found Bitcoin trading more like high-growth software stocks than gold after the coin fell to about $60,000 on Feb. 5 from a peak above $126,000, Cryptopolitan reported.Pandl said Bitcoin is still in its infancy compared to gold, which served as money for thousands of years.As Cryptopolitan reported in June, Grayscale had warned that the market was fragile because of concentrated buying by a small group of digital asset treasury firms. Pandl estimated that if 2% of the $110 trillion generational wealth transfer went into crypto, that would bring in $2.2 trillion of new demand.The smartest crypto minds already read our newsletter. Want in? Join them.