This is the make-or-break level for biotech

It's the sector that has been making investors nervous all month. And now, it's fallen to a critical technical level.

Biotech stocks, which had an incredible run in 2013 and into the first couple of months of 2014, have tanked in March and April. After gaining nearly 93 percent from Jan. 1, 2013, to the end of February 2014, the iShares Nasdaq Biotechnology ETF, the IBB, has fallen 15 percent in the last six weeks. Five percentage points came off on Thursday alone.

(Watch: Meet poster child for momentum stock selloff)

But despite the pain, for Ari Wald, head of technical analysis at Oppenheimer & Co., the drop in the IBB offers a buying opportunity.

"We've been telling clients over the last week it is a positive bullish trade right here, right now," said Wald. "It has been a steep drop, but it is within trend."

That trend is the ETF's 200-day moving average, around the $219-per-share level. The IBB traded around $223 per share on Thursday.

"Support is right there," said Wald, which he sees as the IBB's make-or-break level. "There is additional risk given how much it's run over the last year. If it can't hold that, I'm out."

Chad Morganlander, portfolio manager at Stifel's Washington Crossing Advisors, thinks otherwise. He says he would avoid the biotech sector.

"I think that there are other groups within the health-care industry that have great value," said Morganlander, "that are consistently growing, consistently profitable, [and] well-capitalized."

Morganlander sees the sector's run-up in 2013 bringing valuations too high. He sees the sell-off as continuing, but it may provide a chance to buy down the road.

"I think you could have good opportunity to buy these companies at a better price over the intermediate- and long-term," said Morganlander.

(Read: Top biotech names crushed in market rout)

One company he thinks investors should look at is Gilead Sciences, though with a slight caveat.

"You have to be just a little bit pragmatic about the amount of money you put into it and the percentage in your portfolio," said Morganlander. "It's worth a look but keep in mind, it is a high-beta stock and it did have a heck of a run. But, it has come down quite a bit and perhaps now it's time to start looking a little further into that name."

To see the full discussion on the IBB, with Wald on the technicals and Morganlander on the fundamentals, watch the video above.

[Disclosure: Stifel makes a market in the securities of Gilead Sciences.]

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