Biotech earnings season Is in full swing, and is serving up some incredible volatility across the sector. Companies large and small are beating or falling short on estimates, and offering insights into their operational pipelines, which is – in turn – setting the tone for their respective near term biases.  As we head into the U.S. Open on Wednesday, here is a look at two of this week’s biggest movers so far – Valeant Pharmaceuticals Intl Inc (NYSE:VRX) and Endo International plc – Ordinary Shares (NASDAQ:ENDP) –  and a discussion  as to what’s driving the volatility in each. Here goes.

We will kick things off with Valeant. Valeant has dominated biotech headlines for more than 12 months now, having initially hit press based on a number of investigations into its pricing strategy and some dealings with a pharmaceutical supplier and manufacturer that have now been resolved. It maintained its headline grabbing position by losing a large portion of its market capitalization throughout the majority of 2015 and early 2016 and weighing heavily on Bill Ackman’s Pershing Square position. Now, it looks as though things may be looking up slightly. Not a full recovery, but a bounce at least. The company gained 22% on Tuesday, as it reported second quarter 2016 earnings and outlined a restructuring plan that should see it pay off some of its debt. Valeant’s $30 billion over has been the root of much discussion as late, as the potential for default looms. In response to this potential, it looks as though the company is going to auction off a number of its core assets, as well as some satellite operations, and double down on just a few of its key revenue drivers. There is still some uncertainty surrounding the company’s backroom operations – reports of a insider dinner meeting just last week surfaced yesterday, a meeting that probably shouldn’t have taken place given the fact that the company’s management is supposed to be subject to the traditional quiet period that precedes an earnings release –  but markets seem to have taken the restructuring  plan as a step in the right direction. From a quantitative perspective, revenues came in a $2.4 billion – a decrease of 11% on the comparable quarter during 2015, and net loss came in at $302 million versus the $53 million reported a year earlier.  Not great numbers, but these aren’t what defines Valeant right now.

Moving on, let’s look at Endo International. This one is also an earnings report driven move, but from a far more traditional standpoint. The company reported second-quarter earnings far in excess of analyst expectations, and announced that a former senior vice president at Biogen Inc (NASDAQ:BIIB) would be taking over its branded pharmaceuticals unit. Looking at the numbers, revenues came in for the quarter at $921 million versus analyst expectations of $864 million, while earnings hit $.86 per share – again up on the $.74 per share analyst expectations. The company started the day trading around the $18 mark, but gained on heavy volume post-release to reach highs just ahead of $23 a share, and close out the session for a little over $22 a share.

The big question now is whether Endo can maintain this trend. The company reached 2015 highs in the $93 range, and has since declined more than 76% to current levels. This is not exclusive to Endo, the wider biotechnology space has suffered over the last year especially, but there are a number of companies in the space that have staged a recovery earlier than others. Endo is bringing up the rear somewhat, and its shareholders are likely getting impatient. The latest bounce will be some welcome relief, but Endo will have to meet its (now revised) full-year guidance in order to maintain its current momentum. This guidance sets out a target range of between $3.87 billion and $4.03 billion, as things stand.

So there we go. It’s been a busy week in biotech so far, and chances are we are going to see many more shares trade hands before the week draws to a close, and some double-digit movements as a result. We’re watching these two closely as the week progresses.