As of 07/19/2019
Industrials: 27,154 68.77 0.3%
Transports: 10,604 +66.69 +0.6%
Utilities: 820 11.25 1.4%
Nasdaq: 8,146 60.75 0.7%
S&P 500: 2,977 18.50 0.6%

YTD
+16.4%
+15.6%
+15.0%
+22.8%
+18.7%

26,500 or 28,000 by 08/01/2019
10,000 or 11,000 by 08/01/2019
850 or 800 by 08/01/2019
7,950 or 8,500 by 08/01/2019
2,900 or 3,075 by 08/01/2019

As of 07/19/2019
Industrials: 27,154 68.77 0.3%
Transports: 10,604 +66.69 +0.6%
Utilities: 820 11.25 1.4%
Nasdaq: 8,146 60.75 0.7%
S&P 500: 2,977 18.50 0.6%

YTD
+16.4%
+15.6%
+15.0%
+22.8%
+18.7%

26,500 or 28,000 by 08/01/2019
10,000 or 11,000 by 08/01/2019
850 or 800 by 08/01/2019
7,950 or 8,500 by 08/01/2019
2,900 or 3,075 by 08/01/2019
 
Revised on 6/29/18.
This article describes my analysis of the bearish butterfly pattern as described by publicly available information and common sense rules to determine valid patterns. Additional rules may or may not improve performance. I tested the pattern using only the below identification guidelines.
Bearish Butterfly

Important Results for the Bearish ButterflyOverall performance rank (1 is best): Not ranked
Break even failure rate: *30%
Average drop: *12%
Pullback rate: 57%
Percentage meeting price target: 29%
The above numbers are based on up to 601 perfect trades in bull markets. See the glossary for definitions. * This is measured from point D, downward. For downward breakouts (a close below the bottom of the pattern), the break even failure rate is 20% and the average drop is 14%. 
Characteristic  Discussion 
The Bearish Butterfly Retraces

XAB  Price drops from X (see figure on the right, not drawn to scale) to valley A, then retraces up to B. The BA retrace of XA measures 78.6%.  
ABC  Price retraces from valley A to peak B then drops to C. Retrace BC as a function of BA should be a Fibonacci ratio between and including 38.2% to 88.6%. I list the qualifying ratios in the chart.  
BCD  After peaking at B, price drops to C followed by an extension to D. The DC/BC extension measures one of the Fibonacci ratios from 161.8% to 224%.  
XAD  The extension AD as a percentage of XA is 127 but I allow plus or minus 3 percentage points (124% to 130%) of this to qualify. 
The bearish butterfly pattern follows the ratios listed in the figure and as described in the above table. You'll need a computer running pattern finding software to locate them.
Trading Tactic  Explanation 
Fibonacci  Use the length of the XA move to help predict the price at which the stock will turn at D. AD should be 1.27 times as long as XA. 
Short  Once price turns at D, short the stock. Because this pattern has such a high failure rate (30%), I don't suggest shorting a stock only because it shows a bearish butterfly. Find other reasons why you think the stock will drop. 
Stop  Use a close above D as the stop location. 
Measure Rule  The height of the pattern subtracted from the bottom of the pattern gives a target. This works 29% of the time for patterns with downward breakouts. 
Let's take a look at a trading example.
I show the butterfly on the daily chart of Teva Pharmaceutical. X is at 32.4831.72, A is at 28.4927.60, B is at 31.8330.36, C is 30.9330.03 and D is 33.8232.18, high to low, respectively on the peak or valley. Price reaches the low (L) on 9/6/2017 at 15.22, for a drop of 55% below the high at D.
The AB retrace of XA should be 78.6%. I found the highlow range at peak B includes the 78.6% value, so I count it as a valid retracement.
For the math, using the high at X and low at A, high at B and low at A gives (31.83  27.60)/(32.48  27.60) or 87%. Using the low at B changes the answer to 57%. Because the highlow range on the price bar at peak B includes the 78.6% ratio, I accept that the price bar at B includes the correct Fibonacci retracement for the butterfly.
I use the same methodology for the other ratios: BC/BA, DC/BC. Ratio DA/XA must be within 3 percentage points of the target which it is exactly in this example. That is, DA/XA = (33.82  27.60)/(32.48  27.60) or 127%.
I tried other methods to identify the Fibonacci turns, but this highlow range worked best and it makes intuitive sense. So that's what I used for all butterfly recognition selections.
Would you be able to spot this as a butterfly if the labels were not attached?
 Thomas Bulkowski
See Also

Butterfly is a registered trademark of Scott Carney.
If it's not broke, fix it until it is.