Just like that, the S&P 500's (^GSPC -0.22%) worst loss in nearly two weeks was wiped out with a modest gain that wound up retracing more than half of Tuesday's loss.

The interesting aspect of Wednesday's gain is that it followed a significant worsening in economic data which normally would have implied downside pressure.

No report stood out as more of a sore thumb than the final estimate for U.S. GDP in the first quarter. Revised down from an initial gain of 0.1% to a contraction of 1% in the second estimate, the final GDP reading for the quarter came in at a decline of 2.9%, which was significantly worse than Wall Street's forecast of a 1.8% decline. This looks to be almost entirely the result of colder weather affecting spending and manufacturing, but it's a swift kick in the pants for optimists who are looking for strong signs of economic growth as QE3 is slowly wound down.

Durable goods orders for May also disappointed, with a 1% drop in May compared to a revised-down expansion of 0.6% in April. Excluding extremely costly transportation items, core durable goods still declined by 0.1% -- a cause for concern that consumers' appetite for larger and more expensive goods may be waning.

Finally, the weekly release of the Mortgage Bankers Association's Mortgage Index showed a decline of 1% from the previous week. This follows a 9.2% tumble in the prior week. While fluctuations in loan originations (i.e., mortgages and refinancing) are normal, witnessing a drop in mortgage servicing needs with lending rates nearing their lowest levels in a year is a potentially worrisome sign for the housing sector.

Despite this trio of concerns, the S&P 500 still managed to jump by 9.55 points (0.49%) to close at 1,959.53.

Topping the charts of all individual stocks Wednesday was clinical-stage biopharmaceutical company Aerie Pharmaceuticals (AERI), which skyrocketed 28.3% after it announced positive phase 2b data for investigational glaucoma therapy roclatan. Roclatan hit all of its clinical endpoints in the study, showing a 34% reduction in mean diurnal intraocular pressure compared to the baseline measurement at day 29 (it was a four-week treatment). Furthermore, roclatan was compared to latanoprost (the generic name for Xalatan), the most commonly prescribed glaucoma medication, and it outperformed latanoprost from an efficacy standpoint at each step along the way. Aerie plans to begin phase 3 trials involving roclatan soon, and may look to license the drug outside the U.S.


Source: Convergencia Democratica de Catalunya, Flickr.

As I noted earlier on Wednesday, the simple fact that it's outperforming latanoprost with predominantly mild adverse events is an extremely positive sign. It could mean that roclatan has future blockbuster potential, as Xalatan was a billion-dollar drug. But investors would be wise to understand that a new drug application isn't likely to occur before mid-2016, and an approval could come another six-to-10 months later. In other words, catalysts could be few and far between, which makes chasing Aerie's run fairly risky, in my opinion.

The remaining top stocks on Wednesday both came from the broadcasting sector, with Sinclair Broadcast Group (SBGI 2.72%) and Nexstar Broadcasting Group (NXST 1.95%) advancing by 15.6% and 13.5%, respectively.

The big surge came on the heels of a ruling by the Supreme Court that Aereo, an Internet TV provider, was operating illegally. Aereo had been picking up over-the-air TV signals and selling broadcasting content to Internet users for $8 per month. However, Aereo wasn't paying any licensing fees to broadcasting companies, which resulted in a handful of lawsuits that worked its way to the Supreme Court.


Sinclair Broadcast Group investor presentation, Source: Sinclair Broadcast.

Wednesday's ruling would invalidate the business model of Internet-TV upstarts harnessing over-the-air TV signals and repackaging them into sellable content unless they strike licensing deals with networks beforehand. For Sinclair and Nexstar, it means their content remains protected, yet it also gives them the flexibility to negotiate deals with Internet-TV start-ups like Aereo to expand their audience reach and increase revenue through licensing fees. In all, this is a solid win for traditional broadcasting companies, and Wednesday's spike higher appears well deserved.