Biotech is getting its mojo back.
The iShares NASDAQ Biotechnology Index ETF (the IBB) is up nearly 5 percent in the last five trading sessions thanks in large part to rallies by Biogen, Gilead, Mylan and Illumnia.
It's a welcome from the last two months, when biotechs became the poster child for all that is wrong with momentum stocks.
So is this simply a dead cat bounce or perhaps the start of a sustainable rally and a good entry point for traders who missed the rally?
"Biotech has been a runaway winner and for a heck of a long time," said Steve Cortes of Veracruz TJM. "It has outperformed the S&P  for six of the last seven years. Until about six weeks ago, it was absolutely on fire. I think this is a healthy pullback."
Cortes noted that unlike some other highfliers, biotech companies have been minting cash. "When I look at Biogen, when I look at Gilead," Cortes said. "Are they expensive stocks? Yes. But they are profitable already."
But, there's another reason why Cortes is bullish in the long-term on biotech companies: the world's aging population. "That is a prosperous future for medicine generally," said Cortes. "So I like health care in general and biotech specifically because that is really to me the most exciting place where demographic trends can result in profits down the road."
(Watch: Biogen barreling down on Alzheimer's)
“Talking Numbers” contributor Richard Ross, global technical strategist at Auerbach Grayson, disagreed with Cortes. He said the weakness in the past two months shows a reversal of the upward trend the IBB saw in the last several years.
According to Ross, the charts show a head and shoulders pattern that in December and saw a break below its neckline in the recent selloff. Not only was its 100-day moving average taken out on the downside, but its 200-day moving average also was broken for the first time since 2012. .
"That's another little inkling that you might have this reversal in trend," Ross said. Though on the longer-term chart, the IBB held its 50-week moving average and a $214 support level, Ross doesn't expect it to last.
"I think this bounce fades and fails," he said. "And, we do break below that 50-week moving average and move considerably lower from there…. I would be looking to sell biotech."
However, going short is not for the faint of heart, according to Ross.
"Keep in mind, these bounces are typically bigger than most expect," said Ross. "It’s not easy to short stocks on the way down but that's what I would try to do here."
To see the full discussion on the IBB, with Cortes on the fundamentals and Ross on the technicals, watch the video above.