Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of HCA Holdings (NYSE:HCA), the nation's largest health care services provider in the country, rocketed to the upside by as much as 11% after raising its outlook for the second quarter and full-year. Following the news, sector peers Tenet Healthcare (NYSE:THC), Community Health Systems (NYSE:CYH), and Lifepoint Hospitals (NASDAQ:LPNT) all jumped on its coattails and rode to gains of as much as 9%, 12%, and 8%, respectively.

So what: According to HCA's early morning press release, it anticipates reporting revenue of $9.23 billion, up nicely from the $8.45 billion reported in the comparable quarter last year. Also adjusted income per share is expected to rise to $1.07 from $0.91 in the year-ago period as adjusted EBITDA climbs to $2 billion. In contrast, Wall Street had only been projecting HCA would report $8.86 billion in revenue and $0.92 in EPS. As HCA president and CEO R. Milton Johnson notes in the press release, "Results for the second quarter of 2014 exceeded our internal expectations, both in terms of our core operations and health care reform."

In addition to boosting its Q2 forecast, HCA also revised its full-year forecast in a favorable manner. The company's new guidance projects revenue of $36 billion-$36.5 billion, $7 billion-$7.15 billion in adjusted EBITDA, and $4-$4.25 in EPS. Its previous forecast had called for revenue in the $35.5 billion-$36.5 billion range, $6.6-$6.85 billion in adjusted EBITDA, and $3.45-$3.75 in EPS.

Now what: Though no specifics were outlined, it would appear that the Affordable Care Act, better known as Obamacare, is proving to be everything and more that the hospital sector hoped it would be. Because fewer of the people HCA, and presumably Tenet, Community Health, and Lifepoint, is treating are uninsured, it should result in more collectable revenue for all hospital and surgical care providers either through private party collection or an insurance company. This extra revenue can go straight to the bottom-line since many hospitals have been trying to run lean in anticipation of the implementation of Obamacare.

As a topper, not only would it appear that the ACA is reducing the amount of bad debt hospitals are writing off, but it could also be boosting admissions and visits by the general public. With millions of newly insured people now having the opportunity to see a doctor for preventative care, it's expected that insured citizens won't be as shy about visiting the emergency room if they're sick and their general practitioner can't see them. These ER visits also go straight to fattening up hospitals' bottom-line results.

Ultimately, we won't know the scope of why HCA was so successful for two more weeks, which is when it reports its Q2 results. However, I would venture a guess that its full-year estimates may still be conservative. Keep in mind this is a company that wrote off nearly $3.8 billion as uncollectable in 2012, so there's plenty of room for improvement still. I would ensure you keep HCA high on your watchlist.