We're seeing the exact same setup in shares of toymaker Hasbro (HAS - Get Report) right now. Like CGG, Hasbro has a horizontal resistance level above shares - at $48 in this case - and uptrending support to the downside. The key difference here is that Hasbro's triangle is more conventional than the one in the French oil stock. A breakout above $48 is the signal to become a buyer.
Whenever you're looking at any technical price pattern, it's critical to think in terms of buyers and sellers. Triangles and other price pattern names are a good quick way to explain what's going on in this stock, but they're not the reason it's tradable - instead, it all comes down to supply and demand for shares.
That resistance line at $48 is a price where there's an excess of supply of shares; in other words, it's a place where sellers have been more eager to take recent gains and sell their shares than buyers have been to buy. That's what makes the move above it so significant - a breakout indicates that buyers are finally strong enough to absorb all of the excess supply above that price level. Wait for that signal to happen before you jump into this stock, then it makes sense to put a protective stop in place at the 50-day moving average.