All the kings horses and all the kings men may not be able to bring down the S&P 500 (SNPINDEX:^SPX) ever again. Sure, it's a bit of a stretch as far as nursery rhymes go, but it's fairly appropriate considering how few meaningful corrections the S&P 500 and investors have endured during the past two years.

While optimists were unable to hold their gains into the close, the S&P 500 still managed to vault to a fresh all-time intraday high despite the lone bit of economic data today being modestly negative. Earlier this morning, the Mortgage Bankers Association released its weekly loan origination figures, showing that total originations, which include new mortgages and refinancings, dipped 1.2% last week. Mortgage originations have had a nice rebound in recent weeks, so this drop isn't too worrisome; however even subtle rises in lending rates have squashed loan originations during the past year. It's a situation that bears close monitoring.

By day's end, it was clear that optimists needed a bit of a breather, with the S&P 500 retreating modestly by 2.13 points (-0.11%), to close at 1,909.78.

Leading all stocks to the upside today was small-cap fuel-cell products producer Ballard Power Systems (NASDAQ:BLDP), which gained 19% on the day. Its gains primarily came on the heels of positive analyst commentary from Stifel with regard to one of Ballard Power's fuel-cell peers. Specifically, Stifel mentioned that declining costs in the industry could make the electricity generated by fuel cells more attractive. Despite riding the coattails of its peers higher, and falling more than 50% from its 52-week highs, Ballard Power still doesn't look particularly attractive to me, even here. Although its revenue is growing by 30%-plus per year and its losses are shrinking, I'd want to see improved margins and at least two consecutive quarters of profitability before I'd consider a fuel-cell products developer for my portfolio.

Source: Phil and Pam Gradwell, Flickr.

Following behind Ballard Power was biopharmaceutical company PTC Therapeutics (NASDAQ:PTCT), which added 15.1% despite no readily apparent news. However, just because there was no news today doesn't mean PTC Therapeutics hasn't been making waves with translarna, known as ataluren in the U.S., its investigational nonsense mutation Duchenne muscular dystrophy (nmDMD) drug. Last week, translarna received a positive opinion from the EU's advisory panel and could, within the next three months, be approved throughout Europe. It would also mark the first time an nmDMD-specific drug has been approved. Based on its phase 2b studies, I have a hard time believing the European Medicines Agency won't give its thumbs-up to translarna, but I would still suggest investors wait for a sizable pullback before even considering risking their money in this stock.

Source: VIVUS.

Finally, sticking within the biotech arena, VIVUS (NASDAQ:VVUS) shares shot higher by 6% after a 13-D filing with the Securities and Exchange Commission from hedge fund Aspen Investment noted that the firm had taken a 9.65% stake in the company, and that it was preparing to possibly make an offer of up to $640 million, or $6.19 per share, to take VIVUS private. Aspen's filing notes that it's not obligated to make an offer, but that it anticipates arranging financing and making a bid prior to June 13. VIVUS had no comment on Aspen's actions.

As for me, I'm dumbfounded why any firm would want to buy VIVUS here with anti-obesity drug Qsymia falling well below all Wall Street sales estimates, and losses at VIVUS not expected to shrink in a meaningful way for years to come. Further, the emergence of Orexigen Therapeutics' (NASDAQ: OREX) Contrave, which has undertaken a far more expansive cardiovascular outcomes study, could put it, if approved by the FDA, in line to garner the lion's share of the weight control management market. VIVUS' future is anything but bright in my book, and I'd consider using today's rally to head for the exit.