Investors in Cree (Nasdq: CREE) are used to ups-and-downs in share prices. Just look at the past year: Its trading low has been $24.50; its high $76. On Tuesday, shares surged 16 percent. But in between, Cree has at times been hammered even as shares climbed higher.

This is how CNBC’s Jim Cramer summed up Cree after another tumultuous day of trading:

“One of the most dangerous stocks in the world.”

Shares did in fact 22 percent in one day just two months ago.

But on Tuesday after upgrades from Goldman Sachs and Canaccord Equity to “buy,” investors drove Cree up more than $2 from Monday’s close of $60.19 to $62.81 at the open. More than 11 million shares were traded -five times the daily average – as Cree closed at $69.76.

The high for the day was $70.09.

“We believe the pullback in CREE shares provides a compelling entry point in the most pure-play stock within our global coverage levered to secular growth in LED lighting,” wrote Goldman Sachs analyst Brian Lee, according to Street Insider. “We expect near-term stock upside on: (1) a bounce back in gross margins in F1Q14 – particularly in lighting – that we believe should quell renewed investor concerns on structural margin erosion; (2) expansion beyond Home Depot in the US consumer channel starting in early 2014; and (3) continued LED momentum in commercial (e.g., non-resi), consumer (e.g., incandescent bans, rebates) and China – where we separately raise our LED penetration forecasts,”

He set a share target price of $72.

Canaccord, meanwhile, set a price target of $80 with its “buy” rating.

Not every analyst agrees, however, perhaps stressing Cramer’s point.

Raymand James kept Cree at “Underperform,” according to website Fly on the Wall.

Perhaps adding “buy” pressure to Cree shares today is the pre-opening market announcement that its new LED bulbs that are designed as replacements for traditional 60-watt incandescents have received an “Energy Star” rating. That certification means the $10 bulbs are eligible for some instant rebates from utilities in a number of states. According to Cree, the rebates will drive bulb costs under $5.

Cree worked long and hard to break the $10 price barrier, knowing that based on surveys of consumers the price point it needed to hit to strike a chord with buyers.

“Energy Star qualification can enable the Cree LED Bulbs to be purchased with an instant utility rebate delivering consumers a quality LED bulb for under $5,” said Chuck Swoboda, Cree’s chairman and CEO, in announcing the rating news. “Cree’s already affordable bulb combined with utility rebates makes switching to LED lighting an easy choice for consumers.”

According to Cree, the LED bulbs will produce big savings. They” look and light like traditional incandescent bulbs, use 84 percent less energy and last 25 times longer than typical incandescents,” Cree says.

Just how well Cree was – or was not – doing in the LED marketplace will become clearer when it announces the latest quarterly earnings on Oct. 22.

And Cree investors will be watching keenly to see if another tumultuous time of trading is at hand.

[CREE ARCHIVE: Check out more than a decade of Cree stories as reported in WRALTechWire.]