KILLED · 20% win rate
Hypothesis
When the fast EMA crosses above the slow EMA the trend has turned; ride it until the death cross. The most-viewed strategy format on trading YouTube.
Math — exponential average
EMA_t = \alpha C_t + (1-\alpha)\,EMA_{t-1}, \qquad \alpha=\tfrac{2}{n+1}
The cross is a lagging filter of a lagging filter — by construction it fires after the move.
Method
Long on 9>21 cross, exit on reverse cross or 48h. Same universe / friction / split as N-109. n = 9,373.
Results
| Trades | 9,373 |
| Win rate | 20% |
| Mean net per trade | −0.18% |
| Profit factor | 0.67 |
| t-statistic | −7.7 |
Why it failed
- On 5m crypto the cross fires dozens of times per week per symbol; four of five entries are chop, and the one real trend does not pay for the other four after fees.
- The classic defence — "use it on higher timeframes" — reduces n so far that survivorship and window luck dominate any course-seller's screenshot.
A 20% win rate with 2:1-style exits nets −0.18%/trade on nine thousand trades. The golden cross is a lagging description of the past, not a forecast.
Any signal built purely from smoothed price is late by construction. Late + fees = negative, regardless of how clean the chart examples look.