After a rough week last week, shares of AVEO Oncology (AVEO) are up 15% at 11:52 a.m. EDT on no apparent news.

AVEO Chart

AVEO data by YCharts.

Considering there didn't seem to be a reason for AVEO to go down last week and with data expected soon, it seems investors don't want to miss the boat.

So what

One possibility for the drop is that a large shareholder decided to trim their position, requiring a lower share price to find enough buyers to fill the sale. Seeing value, shareholders have grabbed shares today.

Today's move might also been caused by a short squeeze if day-traders shorted shares last week trying to jump on the momentum of a lowering share price. When the momentum changes, the short-sellers have to buy to cover their shorts, resulting in a temporary increase in buyers that drives up the share price.

A female doctor talking to a male patient lying in a hospital bed

Image source: Getty Images.

Now what

No matter what the reason for the volatility, long-term investors should be focused on AVEO's Fotivda, a drug to treat renal cell carcinoma -- a form of kidney cancer -- which was launched in the European Union in November by partner EUSA Pharma.

For the U.S. approval of Fotivda, the next big event will come from a readout of the TIVO-3 trial expected sometime this quarter. TIVO-3 is comparing Fotivda to Bayer's Nexavar in patients with refractory advanced renal cell carcinoma. AVEO plans to combine the data from TIVO-3 with results from TIVO-1 in patients with previously untreated renal cell carcinoma to gain approval as both a first- and third-line treatment for advanced renal cell carcinoma.

In October, the company told investors to expect the TIVO-3 results in the first quarter, but the estimate got pushed back to the second quarter, suggesting that patients are progressing slower than previously expected. While that could be good news, keep in mind the time frame is based on the progression of both treatment groups. It's possible that patients treated with Nexavar are the ones progressing slower than anticipated, which would make it harder to show that Fotivda is working.

Fortunately, investors won't have to wait too long to find out.