Interesting comment on the "megaphone" a pattern that is new to me.
I had been wondering about what appears to be a back to front pennon/triangle in BHP. Normally patterns converge then break - recently the opposite seems to be occurring.
Seeing BHP is the elephant in the living room as far as materials is concerned - the megaphone in the materials index makes sense.
A Megaphone Top is a relatively rare formation and is also known as a Broadening Top. Its shape is opposite to that of a Symmetrical Triangle. The pattern develops after a strong advance in a stock price and can last several weeks or even a few months.
A Megaphone Top is formed because the stock makes a series of higher highs and lower lows. The Megaphone Top usually consists of three ascending peaks and two descending troughs. The signal that the pattern is complete occurs when prices fall below the lower low.
Underlying Behavior
The creation of the pattern reflects a period of time when bulls and bears are battling to gain control of the stock. The pattern occurs after the bulls have been charging and driving the stock price appreciably higher. During the formation of the Megaphone Top, however, bears are exerting increasing influence on the stock and causing it to set a series of lower lows. The increasing volatility eventually creates a sense of uncertainty, leads to profit-taking, and deters some of the bulls from making any further commitments.