17 trades in 91 seconds

Stocks sold off Wednesday, a day after S&P 500 saw its biggest rally of the year, and the CNBC "Fast Money" traders saw reasons to be cautious.

Reports of gunfire in Canada's Parliament and the fatal shooting of a soldier also appeared to weigh on the market.

The S&P closed at 1,927.11, down 0.73 percent, while the Dow Jones Industrial Average declined 0.92 percent to end the day at 16,461.32. The Nasdaq slipped 0.83 percent to 4,382.85.

Read MoreStocks end sharply lower; oil, Canadian shooting cited

Meanwhile, crude oil moved down $1.97 to end up at $80.52 per barrel, its lowest level since June 2012.

"When you see oil at noon start to tip over and went from $82 to $80, that's the biggest part to why this market really started to flip to the downside," OptionMonster's Pete Najarian said.

Najarian noted that the VIX had traded up 11 percent to 17.87, just a week after it had topped 31.

"The volatility is volatile," he said. "Headlines are leading us all the way."

Private Advisor Group's Guy Adami said that lower oil prices could be problematic.

"I'm in the camp that if oil were going down for the right reasons that would be a good thing," he said, adding that lower demand was a negative sign. "I don't think it augurs well for the economies globally. I still think we're in this huge deflationary period. I think interest rates bear that out. So, I'm not as constructive on the price of oil going lower."

But Adami eyed one stock in the sector.

"I think Exxon is really interesting on a valuation level," he said.

Brian Kelly of Brian Kelly Capital cited the decline in Dow Chemical's stock price.

"Dow should be one of those companies that should be benefitting from lower input costs," he said.

But another ticker kept him from becoming too negative on the market, Kelly added.

"TLT was flat," he said. "And if there's one thing that would get me ultra-bearish, and I'd zip that bear suit up real right, is if we got rising rates and a bad economy."

Traders on the floor of the New York Stock Exchange.
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Traders on the floor of the New York Stock Exchange.

RiskReversal.com's Dan Nathan was avoiding oil stocks.

"I don't think you get near them," he said. "I don't think you want to be in large U.S. multinationals."

A sentiment change might be in the works, Nathan added.

"I'm actually short the DIA, that is the ETF on the Dow," he said.

One stock Nathan exited was AT&T.

"I sold it before the results today because if you're a consumer, you see the price war that's going on," he said. "It's evident in the numbers right here. I think it's going to be sloppy in between Verizon, T-Mobile, AT&T and Sprint for some time now, and I don't think this is a space you want to be in unless you have much longer time horizon."

Another stock he avoided was DDD.

"People, this is what it looks like to see a bubble burst right here," he said. "This stock, triple-D, is down 60 percent on the year. The sentiment couldn't have been higher coming into the year. They keep telling us that demand's really good, but they missed executing, obviously."

Kelly said that he also was steering clear of such 3-D printing stocks as DDD, SSYS andXONE.

"I bought a whole basket of them, thought I was going to own them for five years. Turns out, it was about five weeks because the stocks just looked like absolute death," he said. "So, I really like the space. I think there's huge potential, but when the stocks are acting like death, you have to pull the ripcord and move on."

Adami cited the "huge short interest" in DDD but added that the recent low of $30 would be a place to possibly buy it back.

Najarian said he saw another name looming over those stocks.

"If you look at who's really stealing share right now, it's Hewlett-Packard," he said.

YELP — Nathan noted the "ridiculous valuation" in the stock.

"When you have this sort of deceleration, watch out below," he said. "The thing probably bottoms out at $50 near-term, the low from early May."

AMD — Najarian noted increased put buying and a recent 52-week low in the microchip name.

"People continue to see more downside coming from AMD," he said. "I'm not in this trade, but I can't blame people."

IRBT — Shares of iRobot jumped 14 percent to close at $36.04. Adami said the stock could continue to climb.

"Great quarter. Great guidance," he said. "Listen, I know valuation's a little bit ridiculous, but I also think the stock could trade between $42 and $45. Then you pull the ripcord."

BRCM – Najarian said it might be time to get out of Broadcom.

"This was a stock that was brought down last week with Microchip and all the rest of them," he said. "It's made such a run right now, I think you can wait and then you'd have a better opportunity a little bit lower."

ANGI — Angie's List was a no-touch for Kelly.

"One might say that they got a bad review from Wall Street," he said. "I would stay far away from this name. I think Angie's List and the electronic garage sale they call eBay are problems."

VMW — VMWare appears to have further to fall, Nathan said.

"This is not one I would try to pick a bottom in," he said. "I think you want to wait, probably another 10 percent from here."

YHOO — Nathan said that Yahoo had seen double the average daily volume of options, with twice as many calls as puts. In particular, he noted one seller of 10,000 November 50-strike calls for $0.50.

"When you look at the chart here, that break-even is well above current levels, 20 percent higher here. So, that looks like a pretty safe premium sale over the next few weeks," he said.

Najarian remained positive on Yahoo.

"I'll still stick with it. I still like it," he said. "And I think when you look at the composite, the whole company as a whole, not just the earnings but the whole company, I think this thing's still close to $50."

Adami also saw more upside.

"Somewhere between $45 and $50 is where it goes," he said. "The quarter was good enough. I think Yahoo goes higher."