There have been just eight trading days so far in 2012, so I thought I may have been jumping the gun a bit when I looked to see what the biggest year-to-date winners have been.

But even when I limit the results to companies with market caps of $1 billion or more, there have already been some huge winners, including a stock-price double!

Company

Gain Since Friday, Dec. 30, 2011

Inhibitex (Nasdaq: INHX) 122.6%
Dendreon (Nasdaq: DNDN) 88.8%
Idenix Pharmaceuticals (Nasdaq: IDIX) 75.4%
Regeneron Pharmaceuticals (Nasdaq: REGN) 39.6%
IPG Photonics (Nasdaq: IPGP) 38.2%

Source: S&P Capital IQ.

Can you discern a pattern here? These first few trading days have been dominated by pharma and biotech stocks. Motley Fool Rule Breakers pick IPG Photonics is the only non-bio/pharma stock that sneaks into the top five (at No. 5).

As always, big, often binary events drive the space. Let's see how these winners have been winning.

Inhibitex is being bought out by Bristol Myers-Squibb for a serious premium (163% above previous close), and Idenix has been riding buyout rumors higher.

Dendreon isn't relying on the kindness of strangers, though. It spent the latter part of 2011 getting hammered on weak initial sales for its Provenge cancer drug. Lowered expectations set the stage for exceeding those expectations with a sales surprise. Up from their lows, shares still sit at less than half of where they were before August's beatdown.

As my fellow Fool Brian Orelli put it, Regeneron was up after posting a year's worth of sales in one month off the successful launch of Eylea, a drug to treat age-related macular degeneration.

IPG Photonics, like Dendreon, is up sharply off of lows. Apparently, the street likes what it heard from management at the Needham Growth Conference.

IPG Photonics has had a good recovery, but the big 2012 winners out of the gate so far have been concentrated in health care. If you'd like to read up on another company looking to profit from healing the world, check out "Discover the Next Rule-Breaking Multibagger." Read it now!