Align Technology Inc

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

The strength looks broad-based rather than freakish: its average (+6.2%) and median (+7.1%) sit close together, so no single blow-out year is flattering the figure. No month is steadier: November's returns vary by just 6.6% year to year, and even its worst November in 10 years lost only 7.5% — the gentlest downside anywhere on its calendar. Better still, that strength is the stock's own and not just a buoyant market — November has outpaced the S&P 500 by +3.9 points on average. Few peers keep such company in November — the typical stock clears it just 62% of the time.

It doesn't stand entirely alone — February, March, and April have leaned firm as well, if less emphatically. At the other end of the calendar, October has been the soft spot — the weakest of 3 months that average a loss (−1.0%), and the edge isn't year-round — the stock has trailed the S&P 500 in September, October, and March. Its roughest month on record was a −43.5% October in 2018 — a reminder of how hard even a seasonal name can fall.

Reassuringly, the tendency has held its shape: the recent five years still track the years behind them.

For a stock this dependable in November, 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.