This chart says it's time to buy oil stocks: Analyst By: CNBC.com News April 10, 2015 at 06:00 AM EDT The oil service sector just enjoyed a "very important breakout," says Evercore ISI's head technician. Here's why major upside could be ahead. Read More >> Related Stocks: Diamond Offshore Drilling Halliburton Co Schlumberger Ltd Transocean Ltd