Schlumberger’s post-earnings slump has driven the stock down to a key support area. Here’s how to trade it.

Schlumberger Ltd. reported a net loss of $204 million, or a loss of 15 cents per share, for the fourth quarter, after a loss of $1.02 billion, or an 81 cent per-share loss during the same quarter a year ago. Adjusted earnings for the quarter came in at 27 cents per share, in line with FactSet’s 27 cents consensus.