Rules (fixed before looking at results, applied to each stock's price relative to the S&P 500 so market-wide rallies do not count):

• Base: the 52 weeks before the knee trend at most +10% a year (last 6 months at most +15% a year), and the base's high is at most 2× its low.
• Rise: the price reaches 2× the base level within 1 to 12 months of the knee.
• Sustain: for the next 26 weeks the median stays at or above 2× and never falls below 1.6×.
• Liquidity: base price at least $3 and median daily trading at least $1M.

The knee is placed by fitting a two-segment line to weekly log prices; every rule is checked against the year right before that knee. Scan of ~12,000 US stocks with FMP prices, 2016 to September 2026.

Every match, grouped by what drove it

Within each group, earliest knee first. Each chart shows 6 months before its base year to 9 months after it first reached 2× (use the range control beside a title to widen it): month-end share price and price relative to the S&P 500 scaled to the price at the knee. The shaded span is the base year, the accent line the knee, the other line the month it first reached 2×. Drivers were labelled after the fact by a model and reviewed by hand; they describe what happened, not what was knowable at the knee.