Grayscale Bitcoin Trust (BTC)

This is a fund you can almost set a calendar by, and October is the anchor — it has closed higher in 8 of 10 Octobers, the steadiest beat on its year.

The strength looks broad-based rather than freakish: its average (+15.8%) and median (+14.9%) sit close together, so no single blow-out year is flattering the figure. Few months are steadier: October's returns vary by just 17.3% year to year, and even its worst October in 10 years lost only 12.8% — the gentlest downside anywhere on its calendar. Better still, that strength is the fund's own and not just a buoyant market — October has outpaced the S&P 500 by +14.8 points on average. Few peers keep such company in October — the typical stock clears it just 53% of the time.

It doesn't stand entirely alone — February, April, and May have leaned firm as well, if less emphatically. On the other side of the ledger, August is the year's low point, though even there the fund has stayed positive on average (+9.8%), a sign every month leans up, and the edge isn't year-round — the fund has trailed the S&P 500 in September, January, and March. Its roughest month on record was a −42.0% March in 2018 — a reminder of how hard even a seasonal name can fall.

One run worth flagging just ended: a 6-year streak of positive Octobers was snapped by a −6.7% close in 2025. Reassuringly, the tendency has held its shape: the recent five years still track the years behind them.

For a fund this dependable in October, the sharper question is the rest of the year — outside its strong stretch, the calendar gives far less to lean on. With returns that swing hard year to year, the signal is best held loosely.