I backtested Wyckoff accumulation signals across 185 stocks over 20 years. 13,000+ signals later, here’s what I found.

Most people use Wyckoff theory as a loose framework. Look for a spring, wait for a sign of strength, try to spot the markup. I wanted to know if it actually works when you quantify it and remove all the subjectivity.

So I built a system that scans for specific Wyckoff accumulation events in price and volume data. Selling Climax on heavy volume where smart money absorbs panic selling. Secondary Test where price revisits the lows on declining volume showing sellers are drying up. Automatic Rally. Sign of Strength where price breaks above resistance on expanding volume.

I ran it across 185 US large cap stocks from September 2006 through February 2026. Every signal was measured at 5, 10, 20, and 40 trading days after detection to see if the stock actually went up.

The results across 13,093 total signals:

57.5% win rate at 5 days. 59.3% at 10 days. 62.9% at 20 days. 65.1% at 40 days. The longer the hold period the better the edge. Average winner at 40 days was +9.06% versus average loser of -6.64%. Winners are consistently larger than losers across every measurement window.

The win rate improved further when multiple timeframes confirmed the same accumulation pattern at the same time. All results are statistically significant well beyond p < 0.001 with a z-score of 34.56 on the overall 40 day win rate. This is not noise.

To give you a concrete example. In early 2021 the system flagged ENPH showing a textbook weekly accumulation pattern. Selling climax on high volume, secondary test on declining volume, then a sign of strength breakout. 40 days later ENPH was up over 69%. Same period it flagged MRNA which gained 68% in the same window.

Those are obviously the best case outcomes. The worst signals in that same year lost 25 to 30% in stocks like PYPL and ZM that were rolling over from blow off tops. Q4 2021 was the worst stretch as the whole market topped out. The system does not protect you from macro turns. But the edge is persistent across nearly two decades of data including 2008, the covid crash, and 2022.

The volume part is what most people skip. They look at whether volume is high or low in absolute terms. What matters more is what price does relative to the volume. A wide range down bar on massive volume looks bearish to most people. In Wyckoff terms thats potentially a Selling Climax where institutions are absorbing supply. The key is what happens next. If the stock revisits that level on much lighter volume the sellers are exhausted. Thats the secondary test. When volume expands again on the upside thats confirmation that demand has taken control.

I track every signal going back to 2006 with full return data at every measurement window. Every signal independently verified against live market data. I also log every new detection in real time so you can track whether current signals play out.

Not financial advice. Historical patterns do not guarantee future results. But 13,000 signals over 20 years is a large enough sample to take seriously.