Image source: Getty Images.

Stocks ticked higher on Tuesday, with the Dow Jones Industrial Average (^DJI 0.69%) inching toward the 20,000-point mark and the S&P 500 (^GSPC 1.20%) adding slightly to its double-digit gain for 2016.

Today's stock market

Index

Percentage Change

Point Change

Dow

0.06%

11.23

S&P 500

0.22%

5.09

Data source: Yahoo! Finance.

Price volatility kept commodity funds popular in light overall trading, as a spike in oil prices sent the VelocityShares 3x Long Crude Oil ETN (UWT) up 6%. Higher gold prices produced an 8% bounce for the triple leveraged Direxion Daily Gold Miners Bull 3x ETF (NUGT 3.17%).

As for individual stocks, Fitbit (FIT) and Seattle Genetics (SGEN) stood out with large price swings.

Fitbit catches a break

Fitbit shares spiked 7% following a rare piece of encouraging news about the fitness device maker's holiday sales trends. Its activity tracking software was the second most-popular download among free apps on Apple's iTunes this past week, beating such heavyweights as Snapchat, YouTube, and Instagram. The app hit eighth place in the Android store, just ahead of Pandora's music streaming service. The high ranking suggests millions of Fitbit's products were activated as part of Christmas gift-giving.

Image source: Getty Images.

The company could use some good news. Shares are down over 70% in 2016 on slowing sales growth and slumping profit margins. Fitbit had hoped that a strong product portfolio, including new versions of its Charge and Flex devices, would drive blockbuster fourth-quarter results. However, early indications suggested otherwise. In early November, Fitbit sliced its full-year guidance on what management called "softness in overall demand." More recently, elevated inventory levels at retailers has sparked a drop in consensus revenue estimates for the company's fourth quarter.

The worst-case scenario for shareholders involves broadly weak demand that forces Fitbit to slash prices to protect sales volume. While that's still possible, the fact that usage is spiking on its devices could mean the holiday quarter wasn't as bad as many investors had feared.

Seattle Genetics is put on hold

Seattle Genetics, which specializes in cancer treatments, slumped by 15% after several of its trials were put on hold by the Food and Drug Administration. Two phase 1/2 trials were placed on full hold, meaning no further treatment deliveries, while two others were put on partial hold that ended new enrollments but allowed existing patients to continue receiving treatment at their consent.

Image source: Getty Images.

The biotech said the holds were ordered after six patients out of the roughly 300 treated so far developed hepatoxicity, or liver damage, while taking the aggressive leukemia treatment. Four of those patients died.

It's not clear whether Seattle Genetics' vadastuximab talirine (or SGN-CD33A) was to blame for the deaths, which all involved patients who had also received stem cell transplants. But the trials won't resume until that possibility is ruled out. "Seattle Genetics is working diligently with the FDA to determine whether there is any association between hepatotoxicity and treatment with SGN-CD33A," executives explained in a press release.

The FDA ruling doesn't jeopardize the prospects for the company's biggest drug, Adcetris, which remains commercially available in 65 countries as a treatment for Hodgkin lymphoma. It also doesn't affect other, more advanced clinical trials of SGN-CD33A, including its phase 3 Cascade treatment of older leukemia patients.