Giving new meaning to the term "momentum play," IsoRay (ISR) continued to explode on the morning of Mar. 20, gaining over 30 percent just one day after more-than doubling in value on news that it had successfully treated an aggressive form of cancer in a pediatric patient using its novel Cesium-131 brachytherapy, and during a week that has seen gains of almost 185 percent.

IsoRay tested $3 a share on March 19 before retreating to close at $2.55, good for a gain of 133.9 percent. However, if $3 represented some sort of resistance level for traders, it wasn’t one that held much weight. Share gapped up on very heavy volume at the opening bell on March 20, opening at $3.08 and reaching $3.69 in the first 10 minutes of trading before pulling back.

The trading action remained volatile but still heavily in positive territory, which shares briefly dipping below $3 but mostly remaining over $3.20 apiece.

However, while the price swings are impressive, it’s the volume that’s downright jaw-dropping. More than 55 million shares had changed hands before noon, a truly staggering number when one considers that the entire float for the company is 41.54 million shares. It’s the second straight day where volume exceeded the total float, and shows a fervent interest in the micro-cap stock that the markets had previously not shown. It's entirely possible that the lack of supply for shares is helping to drive this massive run, as pent-up demand leads speculative buyers to increase their bids in order to get their hands on a piece of this relatively small float.

The $3.69 that shares hit in early trading represents a five-year high for the tiny company. The huge volume would seem to indicate that IsoRay is functioning as a popular momentum play for day-traders, but it may also have the product to back it up. The company appears to hold a monopoly on brachytherapy utilizing the Cesium-131 isotope, and many industry watchers see great promise in this treatment system. According to Sujan Lahiri’s Seeking Alpha article that initially carried IsoRay past $1 a share on Mar. 14:

“IsoRay's Cesium 131 cancer therapy is FDA approved, and superior to any cancer therapy by many measures, like the unmatched high 98% to 100% efficacy rate. IsoRay has a monopoly on the Cesium 131 brachytherapy market, and a recent valid CE Mark opens the door for significant revenue growth. Broad unawareness and warrant conversion pushed shares down to an irrationally low level, creating a very favorable risk vs reward investment opportunity.”