signals / EMA 9/21 golden cross
EMA 9/21 golden cross is a long-side study. Fires when the 9-day EMA crosses above the 21-day EMA.
FAQ
What is EMA 9/21 golden cross?
EMA 9/21 golden cross is a long-side study. Fires when the 9-day EMA crosses above the 21-day EMA.
Which names are firing it?
Among mega-caps in the last 5 daily bars: AMZN, WMT, COST, KO, LLY, V, BRK-B, CVX, CVX, PG.
What is the sample?
Hit rates use the same rank engine as /t/spy on a fixed sample (SPY, SPX, QQQ, IWM, AAPL, MSFT, NVDA, TSLA). 8 of those names have a measurable history for this rule. Windows are 5 days, 1 month and 3 months on daily bars. Last bar in sample: 2026-10-12. Method: /methodology. Caveats: /help.
What does EMA 9/21 golden cross measure?
Fires when the 9-day EMA crosses above the 21-day EMA. Underlying math: see How it works on this page. Catalog line: Fires when the 9-day EMA crosses above the 21-day EMA.
What does a firing mean?
A firing is the daily bar where this rule’s condition becomes true (a cross or a flip). It is a study event, not a recommendation to buy or sell. Forward windows on this site are close-to-close with no costs. Study side is long-side (LONG). A positive forward return is a rise in the close after the print — a scoring convention, not a recommendation to buy. Method: /methodology.
Why can the sample be small?
Hit rates need enough dated prints with a completed forward window. A row with fewer than 10 firings is anecdote, not evidence — the same caveat as /help. Slow rules (especially 50/200 SMA crosses) often have single-digit counts on a two-year tape. We do not invent a hit rate when the count is missing. Names in this sample with a measurable history include SPX · QQQ · SPY · MSFT.
How it works
Two exponential moving averages of the daily close: EMA 9 and EMA 21, span smoothing, adjust=False. The rule is a cross of those two averages — not price versus EMA.
Fires when the 9-day EMA crosses above the 21-day EMA.
Definition comes from the rank-rule catalog and the indicator defaults in this repo. Slug ema-9-21-golden-cross is listed on /api/meta.
How to read it
Study side is long-side (labeled LONG on firing chips). A positive forward return on this page is a rise in the close after the print. That is how the event is scored — not a recommendation to buy. A 9/21 EMA cross is a short-horizon trend event. It will print more often than a 50/200 SMA cross. More prints help the sample size and also include more chop. Read the 5-day window separately from the 3-month window; they answer different questions.
Scoring on this site is shared across every rule (5-day / 1-month / 3-month close-to-close windows, side-adjusted). See How it is scored here below. Names in the tracked sample with a measurable history include SPX · QQQ · SPY · MSFT. Those figures are the same rows as the hit-rate table below — not a second ranking. Historical hit rates, not a prediction / not trade advice.
When it fails
- Short EMAs cross often in a range; many 9/21 prints are chop.
- Both sides of the pair (golden and death) can fire in the same swing.
- EMA span smoothing is not the same as Wilder alpha smoothing used on RSI / ADX.
- Past ≠ future. A historical hit rate is not a prediction and not investment advice.
- No costs modeled. Forward returns are close-to-close with no commissions, slippage or borrow.
- Small samples. A row with fewer than 10 firings is anecdote, not evidence.
- Overlap bias. Clustered prints can credit the same later move more than once.
Same caveats as the rest of the site: /methodology · /help.
How it is scored here
On this site every rule is scored the same way: run it over about two years of daily bars, record each firing, and measure what the name did 5 days, 1 month and 3 months later. Sell signals are measured as shorts, so a positive return is a profitable short (side-adjusted). The composite score is 0.6 × average return + 0.4 × (win rate − 50), with longer horizons weighted more. Nothing here is a forecast.
Full catalog: /signals. Method: /methodology. Slug ema-9-21-golden-cross is stable and listed on /api/meta.
Same family: EMA 9/21 death cross
Firing now (mega-caps, last 5 bars)
| Symbol | Last date | Win 1mo | Count |
|---|---|---|---|
| AMZN | 2026-10-07Win 90.9% · n=11FIRED | 90.9%n=11 | 11 |
| WMT | 2026-10-08Win 75.0% · n=12FIRED | 75.0%n=12 | 12 |
| COST | 2026-10-06Win 61.5% · n=13FIRED | 61.5%n=13 | 13 |
| KO | 2026-10-12Win 53.8% · n=13FIRED | 53.8%n=13 | 13 |
| LLY | 2026-10-07Win 54.5% · n=11FIRED | 54.5%n=11 | 11 |
| V | 2026-10-08Win 41.7% · n=12STUDY | 41.7%n=12 | 12 |
| BRK-B | 2026-10-09Win 42.9% · n=14STUDY | 42.9%n=14 | 14 |
| CVX | 2026-10-08Win 30.8% · n=13STUDY | 30.8%n=13 | 13 |
| CVX | 2026-10-06Win 30.8% · n=13STUDY | 30.8%n=13 | 13 |
| PG | 2026-10-06Win 23.1% · n=13STUDY | 23.1%n=13 | 13 |
| GOOGL | 2026-10-06Win 75.0% · n=8STUDY | 75.0%n=8 | 8 |
| MA | 2026-10-09Win 77.8% · n=9STUDY | 77.8%n=9 | 9 |
| AVGO | 2026-10-06Win 44.4% · n=9STUDY | 44.4%n=9 | 9 |
Hit rates on tracked names
Same rank engine as /t/spy, /t/nvda, and /t/spx, restricted to this rule.
| Symbol | Win 5d | Win 1mo | Win 3mo | Count | Last bar |
|---|---|---|---|---|---|
| QQQ | 46.2% | 75.0%n=12 | 60.0% | 12 | 2026-10-12 |
| SPY | 45.5% | 70.0%n=10 | 66.7% | 10 | 2026-10-12 |
| TSLA | 25.0% | 53.3%n=15 | 57.1% | 15 | 2026-10-12 |
| AAPL | 75.0% | 41.7%n=12 | 72.7% | 12 | 2026-10-12 |
| NVDA | 52.9% | 43.8%n=16 | 46.7% | 16 | 2026-10-12 |
| SPX | 50.0% | 77.8%n=9 | 62.5% | 9 | 2026-10-12 |
| IWM | 37.5% | 62.5%n=8 | 57.1% | 8 | 2026-10-12 |
| MSFT | 55.6% | 66.7%n=9 | 28.6% | 9 | 2026-10-12 |
Honest caveats
- Past ≠ future. Everything here is a historical measurement on daily bars, not a prediction and not investment advice.
- No costs modeled. Forward returns are close-to-close with no commissions, slippage or borrow.
- Overlap bias. Signals that fire in clusters get credit for the same move more than once.
- Small samples. A row with fewer than 10 firings is anecdote, not evidence.
Full method: help manual. Interactive chart: terminal.