signals / EMA 9/21 death cross

EMA 9/21 death cross is a sell rule. Sell when the 9-day EMA crosses below the 21-day EMA.

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 always means “following the signal made money.” The composite score is 0.6 × average return + 0.4 × (win rate − 50), with longer horizons weighted more. Nothing here is a forecast.

Full write-up: /help · /methodology. Slug ema-9-21-death-cross is stable and listed on /api/meta.

Same family: EMA 9/21 golden cross

Firing now (mega-caps, last 5 bars)

SymbolLast date Win 1moCount
None of the mega-cap names fired this rule in the last 5 daily bars.

Why it moved

TA on this site tells you which classic rule printed and whether it historically paid. It does not say why the stock moved. Options positioning is often why. SpotGamma maps that.

See why it moved on SpotGamma Free daily Flow Patrol (where funds are buying/selling)

Optional: SpotGamma free tools. Nothing here is trade advice.

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
NVDA40.0%53.3%30.8%152026-08-27
TSLA26.7%53.3%27.3%152026-08-27
AAPL53.8%50.0%27.3%132026-08-27
MSFT36.4%45.5%44.4%112026-08-27
IWM66.7%44.4%37.5%92026-08-27
QQQ40.0%40.0%37.5%102026-08-27
SPX20.0%30.0%37.5%102026-08-27
SPY27.3%27.3%33.3%112026-08-27

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.